Which of the following errors would be reported by the compiler on compiling the program given below?

#include<stdio.h>
int main()
{
    int a = 5;
    switch(a)
    {
	case 1:
	printf("First");

	case 2:
	printf("Second");

	case 3 + 2:
	printf("Third");

	case 5:
	printf("Final");
	break;

    }
    return 0;
}

void *cmp();

#include<stdio.h>
int X=40;
int main()
{
    int X=20;
    printf("%d\n", X);
    return 0;
}

/* myprog.c */
#include<stdio.h>
#include<stdlib.h>

int main(int argc, char **argv)
{
    int i;
    for(i=1; i<=3; i++)
        printf("%u\n", &argv[i]);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>

int main()
{
    int *p;
    p = (int *)malloc(20); /* Assume p has address of 1314 */
    free(p);
    printf("%u", p);
    return 0;
}