Statement-$1$: Molecules that are not superimposable on their mirror images are chiral.
Statement-$2$: All chiral molecules have chiral centers.

• A
  Statement-$1$ is True,Statement-$2$ is True; Statement-$2$ is a correct explanation for Statement-$1$
• B
  Statement-$1$ is True,Statement-$2$ is True; Statement-$2$ is $NOT$ a correct explanation for Statement-$1$
• C
  Statement-$1$ is True,Statement-$2$ is False
• D
  Statement-$1$ is False,Statement-$2$ is True