Recurrent candidiasis and respiratory viral infections from early infancy suggest a significant T-cell immunodeficiency, such as severe combined immunodeficiency. MMR is a live-attenuated viral vaccine and is contraindicated in severe immunodeficiency because vaccine-virus replication can cause serious infection.

Killed IPV, DPT, and TT/Td are non-live vaccines, so they are not contraindicated, although the immune response may be suboptimal. The CDC immunization guidance similarly states that live vaccines are generally contraindicated in severely immunocompromised people.

Topical 5% povidone-iodine to the conjunctival sac and periocular skin is the single most important, standard measure to reduce the patient’s own ocular-surface flora, the main source of organisms causing postoperative endophthalmitis.

Note: Current guidelines also support intracameral antibiotic prophylaxis at the end of surgery, but the option says intravitreal, so A is the best answer. The ESCRS cataract recommendations advise povidone-iodine antisepsis and intracameral antibiotics.