Assertion $(S)$: Rare genes can be preserved in botanical gardens.
Reason $(R)$: Gene banks are developed in botanical gardens.
$(A)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(B)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(C)$ $S$ is true and $R$ is false.
$(D)$ $S$ is false and $R$ is true.

• A
  $A$
• B
  $B$
• C
  $C$
• D
  $D$