Based on the information in the article, which statement must be true?
o
a. the spy plane photos caused the united states to issue a
statement about the soviet union.
o
b. u. s. spying caused cuba to want to increase its military defense
capabilities.
o
c. president kennedy's order to set up a blockade was caused by the
cuban announcement.
o
d. khrushchev's statement was caused by the u. s. government
taking photos of cuba.