Template Function Requirements ?

[Da2]

Yesterday I had an exam, the question was:

What do template functions require (meaning , where T is a must) ?
1) template <class T> void func(T& t);
2) template <class T> T& func();
3) template <class T> void func() { T t ,...... }
4) None of the above

I marked 1 :S, cause I thought that's how you "define" the function to be of the type you currently use......

Should I prepare for the 2nd c++ course ? :(