You are answering a USMLE-style medical question. Question: An 11-year-old child complains of pain in the leg while playing. Blood pressure in the upper limb is 140/90 mm Hg and lower limbs are 110/70 mm Hg. There is a brachiofemoral delay in the pulse. Auscultation shows a loud S1, loud S2, and S4. There is a presence of an ejection systolic murmur in the interscapular area. Chest X-ray reveals the notching of the ribs. What is the most likely diagnosis in this patient? Options: A) Pulmonic stenosis B) Coarctation of the aorta C) Aortic stenosis D) Transposition of great vessels Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.