What is mean of putting some one in your place

It means to like swap out yourself with someone else.

To put someone else in your place is essentially saying, I’m going to have (insert person) take my place instead.

It’s like, sitting out and letting someone else replace you.

Hope this helps!

Let someone know that the person is less important than he or she thinks

The answer is c, because it's referring to you, and then refers to a group of people stopping the flu, which is a clever way of making the viewer feel like they have the impact to stop a disease. (sorry its hard to explain)