Assertion $(A)$ At $300 \ K$,kinetic energy of $16 \ g$ of methane is equal to the kinetic energy of $32 \ g$ of oxygen.
Reason $(R)$ At constant temperature,kinetic energy of one mole of all gases is equal.

• 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 not true
• D
  $(A)$ is not true but $(R)$ is true