Which statement best describes the ovulation phase regarding basal body temperature?

Which statement best describes the ovulation phase regarding basal body temperature?

• A. The newly released egg will live for 72 hours and disintegrate if not fertilized.
• B. The woman will have a low basal body temperature before ovulation and then a temperature increase of 0.4-1°F around ovulation.
• C. The ovum is directly released into the fallopian tube.
• D. Fertilization most commonly occurs at the fimbria.

Answer: (B)

Basal body temperature patterns reflect the hormonal shift that occurs with ovulation. Before ovulation, the temperature stays relatively low, and after ovulation the rise in progesterone causes a noticeable increase—typically about 0.4–1.0°F—which then remains elevated until menses. This pattern—low temperature preceding ovulation with a subsequent rise around the time of ovulation—best matches what is described. The other statements focus on egg viability, the exact point of egg release, or where fertilization occurs, none of which explain the characteristic BBT change linked to ovulation.