<prompt> A 26 year old woman with 32-day menstrual cycle planning for conception regularly checks her body temperature orally using a digital thermometer in the morning before getting out of bed. She noticed an increase in her body temperature on the 18th day of menstrual cycle. This is caused byOestradiolProgesteroneLH peakFSH peak  <response>: The cause of the temperature change at the time of ovulation is probably the increase in progesterone secretion since progesterone is thermogenic. 