During menstruation the level of progesterone in blood is

What are the changes in the oogonia during the transition of a primary follicle to Graafian follicle ?

Transformation of a young follicle into graafian follicle is controlled by

Which one of the following is the correct matching of the events occurring during menstrual cycle?

Given below is a flow chart showing ovarian changes during menstrual cycle. Fill in the spaces giving the name of the hormones responsible for the events shown.

$\boxed{\rm {Primary follicles}}$

$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \downarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \leftarrow \,\boxed A$

$\boxed{\rm {Graafian follicle}}$

$\,\,\,\,\,\,\,\,\,\,\,\,\,\, \downarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \leftarrow \,\boxed B$

$\,\,\,\,\,\,\,\,\,\,\,\boxed{\rm {Ovum}}$

$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \downarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \leftarrow \,\boxed C$

$\boxed{\rm {Corpus leuteum}}$

Changes in $GnRH$ pulse frequency in femail is controlled by circulating levels of