Is the size of C “int” 2 bytes or 4 bytes?

Question

Does an Integer variable in C occupy 2 bytes or 4 bytes? What are the factors that it depends on?

Most of the textbooks say integer variables occupy 2 bytes. But whe

Answer 1

#include 

int main(void) {
    printf("size of int: %d", (int)sizeof(int));
    return 0;
}

This returns 4, but it's probably machine dependant.