Insert the Missing Code in the Following Code Fragment

Insert the missing code in the following code fragment. This fragment is intended to recursively compute xⁿ, where x and n are both non-negative integers:
Public int power(int x, int n)
{
If (n == 0)
{
____________________
}
Else
{
Return x * power(x, n - 1) ;
}
}

A) return 1;
B) return x;
C) return power(x, n - 1) ;
D) return x * power(x, n - 1) ;