The issue that led to jimmy carter's defeat in 1980 was
a. his pardoning of richard nixon.
b. the soviet invasion of afghanistan.
c. his inability to gain the release of american hostages held in iran.
d. the collapse of oil prices.
e. his affair with a white house intern.

Well, first of all, many issues led to his defeat. I would say if you're asking for specifics, some answers to this particular question would be c, d or b, because e didn't happen until Clinton, and a was President Ford. Other than that I don't know what to tell you. You will have to figure it out on your own, or better yet email your teacher.