What exception does LINE A throw?

class ArrayExample

$\{$

public static void main$($String s$[])$

$\{$

int$[]$ a $=\{4,5,6\}$;

int total $=$ a$[1]+$ a$[2]+$ a$[3]$; $//$ LINE A

System.out.println$("$Total $="+$ total$)$;

$\}$

$\}$

a$.$ NullPointerException

b$.$ ArithmeticException

c$.$ No exception will be thrown

d$.$ ArrayIndexOutOfBoundsException