Example:

#include <stdio.h>

int main(void) {
	
	int choice = 2;
	switch(choice){
	    case 1:
	        printf("Case 1\n");
	    case 2:
	        printf("Case 2\n");
	    case 3:
	        printf("Case 3\n");
	    case 4:
	        printf("Case 4\n");
	    default:
	        printf("Case default\n");
	}
	
	return 0;
}

Output

Case 2
Case 3
Case 4
Case default

How to fix?

Use break with each case block.

Correct code:

#include <stdio.h>

int main(void) {
	
	int choice = 2;
	switch(choice){
	    case 1:
	        printf("Case 1\n");
	        break;
	    case 2:
	        printf("Case 2\n");
	        break;	    
	    case 3:
	        printf("Case 3\n");
	        break;	    
	    case 4:
	        printf("Case 4\n");
	        break;	    
	    default:
	        printf("Case default\n");
	}
	
	return 0;
}

Output

Case 2