Among people who experience migraine headaches, some experience what doctors call "common" migraines, whereas others experience "classical" migraines. Siblings and spouses of common migraine sufferers are themselves twice as likely as the general population to experience common migraines. Siblings of classical migraine sufferers are four times more likely than the general population to experience classical migraines, whereas spouses of classical migraine sufferers are no more likely than the general population to experience such headaches.

The information above provides the most support for which of the following hypotheses?

(A) Susceptibility to classical migraines is more dependent on hereditary factors than is susceptibility to common migraines.
(B) Unmarried adults are more likely to suffer from classical migraines than they are to suffer from common migraines.
(C) People who do not experience migraine headaches are unlikely to have spouses who are migraine headache sufferers.
(D) Children of people who suffer from common migraines are not more likely than the general population to experience a common migraine.
(E) Between one-quarter and one-half of the general population suffer from either common or classical migraine headaches.

Oa is A; Two question :
1. Is the correct answer choice typical of such questions where we look for MUST be true or reasonably correct answer choices ?

2. Why B is wrong; I can feel it but want to know precise reason to destroy.