Answer:
There really is no answer. A is a 1/2 truth. B the reasons for not choosing B are given. We know nothing about C or D, but they are likely not true. None of his 3 children had Polio. No mention is made of himself.
I guess B, but a marker could pick anything, the choices are so bad.
Step-by-step explanation:
A isn't true. He lived long after the vaccine was developed.
B. It was a dreaded disease long before he became a doctor. and some 15 years after. (1939 to 1954)
C. We don't know anything about Salk's personal life. C and D are both not part of the same missing piece of information.
D. We don't know if he did or not. The article does not say.