Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A$: $FSH$ acts upon ovarian follicles in female and Leydig cells in male.
Reason $R$: Growing ovarian follicles secrete estrogen in female while interstitial cells secrete androgen in male human being.
In the light of the above statements,choose the correct answer from the options given below:

• A
  Both $A$ and $R$ are true but $R$ is $NOT$ the correct explanation of $A$.
• B
  $A$ is true but $R$ is false.
• C
  $A$ is false but $R$ is true.
• D
  Both $A$ and $R$ are true and $R$ is the correct explanation of $A$.