What will be the output of the following C code?

#include <stdio.h>
void main()
{
    char *str = "";
    do
    {
        printf("hello");
    } while (str);
}

Which control structure is used to repeatedly execute a block of code in C?

A. for loop

B. if statement

C. switch case

D. while loop

In C, what is the purpose of the 'break' statement within a loop?

A. Continue to the next iteration

B. Exit the program

C. Terminate the loop and exit it

D. Skip the current iteration

What is the purpose of the 'else' statement in C's 'if-else' control structure?

A. Execute the 'if' block

B. Execute the 'else' block

C. Execute both 'if' and 'else' blocks

D. Skip the 'if' block

Which control structure is used to make a decision between two or more alternatives in C?

A. switch case

B. for loop

C. if statement

D. while loop