Which of the following examples likely occurred through natural selection?
A.
In a litter of puppies, some puppies have brown fur while others have black fur.
B.
Some humans have hair on the middle part of their fingers, while others do not.
C.
There are several colors of roses, such as red, white, pink, and yellow.
D.
Giraffes have longer necks than their ancestors.

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 : )

b is dominant over the allele for the white fur.