Welcome to your interview.
The question is on your right: C Parameter Passing Differences. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
What are the differences between passing by value, passing by pointer, and passing by reference in C?