When does the first menstrual cycle begin?

If a female experiences menstruation $6$ times in $12$ months under normal conditions,which of the following can be inferred?

Inhibition of secretion of which of the following hormones is necessary for the disintegration of the corpus luteum?

Identify the hormones that are secreted in large amounts prior to ovulation:
$A.$ $LH$
$B.$ $FSH$
$C.$ $Estrogen$
$D.$ $Progesterone$

The following graph shows the relative concentrations of the four hormones present in the blood plasma of a woman during her menstrual cycle. Identify the hormones.

Which one of the following statements is incorrect about the menstrual cycle?