Assertion $(A)$: If heat of combustion of $C_2H_6$ is $X \ kJ \ mol^{-1}$,heat liberated on combustion of $150 \ g$ of $C_2H_6$ is $5X \ kJ$.
Reason $(R)$: Enthalpy is an extensive property.

• A
  Both $(A)$ and $(R)$ are correct,and $(R)$ is the correct explanation of $(A)$
• B
  Both $(A)$ and $(R)$ are correct,but $(R)$ is not the correct explanation of $(A)$
• C
  $(A)$ is correct,$(R)$ is not correct
• D
  $(A)$ is not correct but $(R)$ is correct