Which line contains the first compile error in this code?

$1.$ int$[10]$ arr $=$ new int$[10]$;

$2.$ int sum $=0$;

$3.$ for$($int i $=0$; i $<$ arr.length; i$++)\{$

$4.$ sum $+=$ arr$[$i$]$;

$5.\}$

Group of answer choices

$2$

$1$

$3$

$4$