The correct answer is A. The regulation of metabolism.
Metabolism is an endocrine function that takes place in both the male and female bodies. Ovulation, childbirth and the menstrual cycle are all strictly female bodily functions. The endocrine system is the collection of glands that produce hormones for several functions throughout the body.
Definitely A. Even without knowing what metabolism is, from logical analysing, you would know that males cant stimulate ovulation, childbirth and cant regulate menstrual cycle. So A is the only logical answer.
