How selfish can you be?

I teach an undergraduate class where many of the students want to go to med school. There is a lot of competition...

I take pride to answer my email as quickly as possible and for every answer I provide, I send the question(s) and answer(s) to ALL my students. One student is not pleased by that...he would rather like that I answer his questions only to himself....I bet he reads all the answers of the other students questions...just to get an edge....arghhhh!