President Kennedy's main goal in the United States' 1962 decision to blockade Cuba was to?:
A. encourage Castro to reopen diplomatic relations with the United States.
B. use the CIA to overthrow the Castro government forcibly.
C. encourage the Soviet Union to stop sending soldiers and aid to Castro.
D. force the Soviet Union to remove its missiles from Cuba.
E. force the resignation of Soviet Premier Nikita Khrushchev.