Marcus and Vanessa Have Planned a Romantic Evening of Dinner

Marcus and Vanessa have planned a romantic evening of dinner and dancing. In preparation for the fact that they will make love later in the evening, Vanessa inserts her diaphragm and spermicide before leaving the house at seven. After dancing, she expects to arrive at home with Marcus around midnight. What should Vanessa know?

A) Dancing might dislodge the diaphragm.
B) Her spermicide is only effective for two hours after she inserts it.
C) The diaphragm should be inserted just before intercourse.
D) It is unnecessary to use spermicide.