$\text{Assertion (A):}$ Variance of $4x_1, 4x_2, \ldots, 4x_n$ is $16$ times the variance of $x_1, x_2, \ldots, x_n$. $\text{Reason (R):}$ If $y = ax + b$,then variance of $y$ is $a(\text{variance of } x) + b$. The correct option among the following is

• A
  $(A)$ is true,$(R)$ is true and $(R)$ is the correct explanation for $(A)$.
• B
  $(A)$ is true,$(R)$ is true but $(R)$ is not the correct explanation for $(A)$.
• C
  $(A)$ is true but $(R)$ is false.
• D
  $(A)$ is false but $(R)$ is true.