In C, what statement do you use to output the number 42 to the screen?

To output the number 42 to the screen in C, you would use the printf function. Here's how you can do it:

#include <stdio.h>

int main() {
    printf("%d", 42);
    return 0;
}

Here's a step-by-step breakdown of the code:

1. #include <stdio.h>: This is a preprocessor command that includes the standard input/output library in the program. This library contains the printf function that we use to output text to the console.

2. int main() { ... }: This is the main function where the program starts execution. Every C program must have a main function.

3. printf("%d", 42);: This is the statement that outputs the number 42 to the screen. The %d inside the string is a placeholder for an integer. When printf sees this, it replaces it with the second argument, which is the number 42 in this case.

4. return 0;: This statement signifies that the program has ended successfully. It's not necessary for this simple program, but it's good practice to include it.