$STATEMENT-1$: The plot of atomic number ($y$-axis) versus number of neutrons ($x$-axis) for stable nuclei shows a curvature towards the $x$-axis from the line of $45^{\circ}$ slope as the atomic number is increased.
$STATEMENT-2$: Proton-proton electrostatic repulsions begin to overcome attractive nuclear forces in heavier nuclides,requiring more neutrons to maintain stability.

• A
  $STATEMENT-1$ is True,$STATEMENT-2$ is True; $STATEMENT-2$ is the 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.