Answer:
this is from a movie, here's how you should answer:
"If I give you a paper and tell you to write your name, what would you use? Of course, a pen. That's exactly why you need this. Basically, it's just supply and demand."
Explanation:
The demand in this is to write your name in a piece of paper. But how can you do it without a pen? That's how supply and demand works. Good luck with your interview.
