Answer:
The three serious problems that Jimmy carter faced during his presidency were: B) Iran hostage crisis, D) Soviet Invasion of Afghanistan and E) The end of detente.
Explanation:
Let's analyze the options considering Jimmy Carter was president between 1977 to 1981)
First of all options A) the watergate scandal happened when Nixon was in power, so it's false.
Second, B) Iran hostage crisis happened between 1979 and 1981. While Jimmy Carter was president.
Third, C) option of the Vietnam war ended in 1975. 2 years before Jimmy Carter assumed the presidency.
Fourth, d) Soviet Invasion of Afghanistan. It lasted from 1979 to 1989. So Jimmy Carter lived the first two years o the conflict. That's why he proposed the boycott of Moscow summer Olympic games.
Fifth, E) the end of detente with the Soviet Union and the communists ended in 1979 when president Jimmy Carter boosted the budget and helped Pakistan president to fight Soviet fighters in his country. So, it's right.
Sixth, F) The Cuban Missile Crisis. President Jimmy Carter wasn't president at the time. Nixon was in the office when the Cuban Missile crisis happened.