What will be the worst case time complexity for the following code?

[answerhappygod]

#include <stdio.h>
bool func(int arr[], int n, int sum)
{
if (sum == 0)
return true;
if (n == 0 && sum != 0)
return false;
if (arr[n-1] > sum)
return func(arr, n-1, sum);
return func(arr, n-1, sum) || func(arr, n-1, sum-arr[n-1]);
}
int main()
{
int arr[] = {4,6, 12, 2};
int sum = 12;
int n = sizeof(arr)/sizeof(arr[0]);
if (func(arr, n, sum) == true)
printf("true");
else
printf("false");
return 0;
}
a) O(n log n)
b) O(n2)
c) O(2n)
d) O(n2 log n)