What will be the output of the following C code?

#include <stdio.h>
int main()
{
    const int i = 10;
    int *ptr = &i;
    *ptr = 20;
    printf("%d\n", i);
    return 0;
}

A. Compile time error

B. Compile time warning and printf displays 20

C. Undefined behaviour

D. 10

Answer: Option B