Pauline is correct that "tell" is the right word. In English, "tell the difference" means to see/understand clearly how one thing is different from another. We do not use "make" for that meaning. But we do say "Make a difference" -- but this has a totally different meaning. "Make a difference" means to do something that makes something better. Example: The new striker on the football team really made a difference. Last year, the team was in last place. This year, because of the new striker, the team is in first place. Another example: I want to be a doctor because I really want to make a difference in the world by curing people who are sick.

The correct one is 'tell' because as the speaker you are stating in the sentence because it is period so that's why. Next is if you use 'make' you are like making about something in fact and opinion you want to have another meaning or examples of that.

tell is the true answer. because [make a difference ]descibes "sb does something great ,however,tell a difference is distinguish some different things.