What will be the output of the following C code?

#include <stdio.h>
union u
{
    struct p
    {
        unsigned char x : 2;
        unsigned int y : 2;
    };
    int x;
};
int main()
{
    union u u;
    u.p.x = 2;
    printf("%d\n", u.p.x);
}

A. Compile time error

B. Undefined behaviour

C. Depends on the standard

D. 2

Answer: Option A