Some homework help

If an expectant mother wants to avoid her child being born with cognitive deficits, what should she avoid during pregnancy
a. taking thalidomide
b. flying in an airplane
c. consuming alcohol
d. red meat

I'm stuck on either a. or c. Thalidomide has been discontinued, but it's still in use today for skin treatments, while I think you could still consume small amounts of alcohol with no negative effects while pregnant. What do you guys think?