I'll answer both questions from the images.

Question 1 (first image): "An infectious substance transported in a form capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposed to it is a ________."

Category A infectious substances are those capable of causing permanent disability, life-threatening or fatal disease in otherwise healthy humans or animals. They are assigned UN2814 (affecting humans) or UN2900 (affecting animals only). Category B substances do not meet Category A criteria.

Question 2 (second image): "Packages of Dry Ice must display the following: (select all that apply)"

Per IATA Dangerous Goods Regulations, packages containing dry ice (UN1845) must bear:

UN3549 is Medical Waste, Category A - this is a forbidden substance on passenger aircraft. It is only permitted on cargo aircraft only, not on passenger and cargo aircraft.

The statement says it is permitted on "passenger and cargo or cargo only aircraft" - this is false because it is restricted to cargo only.

A shipper's declaration is NOT required for UN3373 Category B infectious substances.

Key distinction:

This is one of the main reasons Category B has a simpler shipping process compared to Category A.

Per IATA Dangerous Goods Regulations, shippers must arrange with the operator (airline) for each shipment of dry ice to ensure proper ventilation safety procedures are in place.

Dry ice (UN1845) sublimates into CO₂ gas, which can displace oxygen and create a suffocation hazard, especially in enclosed cargo holds. Because of this risk, the operator must be notified and ventilation procedures must be confirmed for every shipment - it is not a one-time arrangement.

When dry ice is used solely as a refrigerant for other goods (non-dangerous), a Shipper's Declaration for Dangerous Goods is not required for the dry ice itself.

However, if the goods being refrigerated by the dry ice are themselves dangerous goods (e.g., Category A infectious substances, flammables, etc.), then a Shipper's Declaration is required for those dangerous goods - not for the dry ice per se.

In summary:

Hepatitis B is an example of a UN3373 Biological Substance, Category B.

Here's why the others are not Category B:

Category B substances are those that do not meet the criteria for Category A - they may cause disease but not permanent disability or life-threatening/fatal illness in healthy people under normal exposure circumstances.

This is the exact definition of Category B - an infectious substance that does not meet Category A criteria. It is NOT generally capable of causing permanent disability or life-threatening/fatal disease in otherwise healthy humans or animals.

Quick comparison:

Per IATA Dangerous Goods Regulations, the "OVERPACK" mark must be displayed in letters a minimum of 12 mm high on the overpack.

Per IATA Dangerous Goods Regulations, Packing Instruction 620 is used for Category A Infectious Substances affecting humans and animals (UN2814 and UN2900) shipped by air.

Quick reference for all packing instructions in this category:

PI 620 requires a triple packaging system: primary receptacle → secondary packaging → rigid outer packaging, with specific quantity limits and documentation requirements.

When DOT and IATA require UN specification packaging for fully regulated medical/biological waste, it must meet Packing Group II performance standards.

Packing Group II represents medium danger - it is the standard required for infectious substances (Category A - UN2814/UN2900) packaging. This means the packaging must pass Packing Group II performance tests (drop, stacking, leakproofness tests) to be considered compliant for shipping fully regulated infectious waste by air.

Infectious Substances (affecting both animals and humans) are classified under Hazard Class 6, Division 6.2.

Quick reference for Class 6:

The other options:

IATA Special Provision A140 applies to infectious substances (UN2814, UN2900, UN3373) and eliminates the requirement to include a technical name alongside the proper shipping name on the package marking.

Normally, many dangerous goods require a technical name in parentheses next to the proper shipping name. Special Provision A140 grants an exemption for infectious substances - to protect patient confidentiality and for biosecurity reasons, the specific technical/biological agent name does NOT need to appear on the outer package.

There are 9 hazard classes in IATA/DOT Dangerous Goods Regulations:

So the answer is 9 classes, several of which are further divided into sub-divisions.

UN1845 is the UN identification number for Dry Ice (Carbon dioxide, solid), Class 9 - Miscellaneous Dangerous Goods.

Quick reference for the other options: