Final answer:
During middle adulthood, women may experience chills due to changes in hormone levels, especially hot flashes and night sweats, associated with the menopausal transition.
Step-by-step explanation:
Based on anticipated physical changes resulting from normal aging in middle adulthood, the change in the female reproductive system that occurs during middle adulthood is d. Chills due to changes in hormone levels, specifically, hot flashes and night sweats. During the menopausal transition, often referred to as peri-menopause, a woman’s menstrual cycle becomes irregular but does not stop entirely. The reduction in the level of progesterone can lead to hyperplasia of the endometrium, increasing the risk of endometrial cancer. Other conditions such as uterine fibroids and irregular bleeding may also occur. The decrease in estrogen levels can cause symptoms like hot flashes, night sweats, trouble sleeping, vaginal dryness, mood swings, difficulty focusing, and changes in hair thickness and distribution.