Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Cis form of alkene is found to be more polar than the trans form.
Reason $(R)$: Dipole moment of trans isomer of $2$-butene is zero.
In the light of the above statements,choose the correct answer from the options given below:

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