What is the process of transformation of spermatids into spermatozoa called?

Which hormone regulates the corpus luteum?

What is the process of degeneration of follicles and oocytes in the ovary called?

The mother germ cells are transformed into a mature follicle through a series of steps. Provide the missing steps in the blank boxes.
$\boxed{\text{Oogonia}} \to \boxed{A} \to \boxed{\text{Primary follicle}} \to \boxed{B} \to \boxed{C} \to \boxed{\text{Mature or Graafian follicle}}$

Spermatogonia undergo a series of cell divisions to produce sperms. Select the correct statements from the following:
$A$. Spermatogonia always undergo meiotic cell division.
$B$. Primary spermatocytes divide mitotically to produce secondary spermatocytes.
$C$. Secondary spermatocytes,through their second meiotic division,produce spermatids.
$D$. Spermatids produce spermatozoa through mitosis.
$E$. Spermatids transform into spermatozoa by spermiogenesis.
Choose the correct answer from the options given below:

The difference between $Spermiogenesis$ and $Spermiation$ is: