During the luteal phase of the ovarian cycle, progesterone secretion peaks and estrogen levels decrease. along with these changes, there is a corresponding increase in a woman's basal body temperature. which of the following hypotheses best explains this phenomenon? a. it is not the increase in progesterone, but the decrease in estrogen that may signal an increase in overall body temperature. this is because the decrease in estrogen reduces the negative feedback signal to the hypothalamus, the thermoregulator for the body. the result is an increase in overall basal body temperature. b. the corpus luteum, formed from the follicle that released the egg, matures. if the egg is not fertilized, the corpus luteum breaks down and is reabsorbed. the process of breaking down the corpus luteum gives off heat energy that is translated into increased body temperature. c. the luteal phase and progesterone secretion in the ovary correspond to the secretory phase of the uterine cycle. during this time, the endometrial lining proliferates. along with this increase in thickness, more blood vessels are formed. the combination of lining and blood vessels increases overall body temperature. d. basal body temperature increase is a function of ovulation. once the egg is released from the ovary, it signals an increase in body temperature to facilitate fertilization because sperm function more efficiently at higher temperatures.