The question is formulated in the way that answering that does not provide any real knowledge. This is a form of idiotic interview or test questions. Such questions should not be answered and even asked at the forum promoting real knowledge, understanding of technology and skills.
The only decent approach would be this: learn this (really simple) topic and do exercise in code to make sure you understand it and can use in practice. Please see:
Even when you learn it all, I would not advise even looking at the questions. They promote thinking along the wrong lines. This is my personal opinion though; may be for some they could be used as some self-control.