Why do most plants appear green?
a. they absorb only photons
b. abosrb mostly red and green light
c. they reflect back what is left of the visible light
d. all the above

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )