Assertion $(A) :-$ Sperm production occurs in the seminiferous tubules.
Reason $(R) :-$ The seminiferous tubules are lined on their inside by spermatogonia and Sertoli cells.

• 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
  Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
• D
  Both $A$ and $R$ are false