The main function of mammalian corpus luteum is to produce
estrogen only
Progesterone and estrogen
Human chorionic gonadotropin
relaxin
As we have discussed in Menstrual Cycle -
Corpus luteum secretes steroid hormones progesterone and estrogen to make uterus suitable for implantation.These hormones maintain endometrium of the uterus
Hence, the correct option is (b).