Question

What data do you need to determine whether the following reaction is spontaneous or not?
4Fe(s) + O2(g) ----> 2Fe2O2(s)

Would it be temperature, delta H and delta S?

Answer 1

You need dG. If you don't have that, you can calculate it from dG = dH - TdS

Answer 2

Should I write both just to be sure or is delta G the only answer I need?

Answer 3

I don't know what your instructions are. One answer is all that you have given; i.e., T, dH and dS because you can calculate dG from those three.
If I had a choice I would choose dG.