Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ diode under reverse-biased condition provides very small current which is nearly independent of voltage until a critical limit at which the current increases drastically.
Reason $R$: Below the critical voltage limit,only majority charge carriers flow which increases drastically above critical voltage.

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