What will be the time complexity of the following code?

#include <stdio.h> 
#include <math.h> 
void PowerSet(char *set, int set_size) 
{ 
	unsigned int pow_size = pow(2, set_size); 
	int count, j; 	
	for(count = 0; count < pow_size; count++) 
	{ 
	     for(j = 0; j < set_size; j++) 
	     { 
 
		if(count & (1<<j)) 
			printf("%c", set[j]); 
	     } 
	     printf(","); 
	} 
} 
int main() 
{ 
	char strset[] = {'a','b','c'}; 
	PowerSet(strset, 3); 
	return 0; 
}

A. O(n 2ⁿ)

B. O(n²)

C. O(n log n)

D. O(2ⁿ) (n is the size of set)

Answer: Option A