Given the following code snippet, what is true about the statement ptr$++?$

int arr$[5]=\{1,2,3,4,5\}$;

int$*$ ptr $=$ arr;

ptr$++$;

ptr now points to arr$[0]$;

$2.$ptr now points to arr$[1]$;

$3.$ptr$++$ results in a compilation error.

$4.$ptr$++$ results in a run$-$time error.