Assertion $(A)$: If $A=10^{\circ}, B=16^{\circ}, C=19^{\circ}$,then $\tan 2A \tan 2B + \tan 2B \tan 2C + \tan 2C \tan 2A = 1$.
Reason $(R)$: If $A+B+C=90^{\circ}$,then $\tan A \tan B + \tan B \tan C + \tan C \tan A = 1$.
Which of the following is correct?

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