You are answering a USMLE-style medical question. Question: A 34-year-old male suffers from inherited hemophilia A. He and his wife have three unaffected daughters. What is the probability that the second daughter is a carrier of the disease? Options: A) 0% B) 25% C) 50% D) 100% Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.