In the Menstrual Cycle, Basal Body Temperature

In the menstrual cycle, basal body temperature

A) rises just prior to ovulation and then falls three days after ovulation.
B) dips slightly just before ovulation and remains slightly lower until menstruation.
C) dips slightly just before ovulation and then rises and remains elevated until menstruation.
D) rises just before ovulation, remains elevated through ovulation, and then drops slightly until menstruation.