It can add both ortho and para since its a activating group attached to it. This problem is testing you to know that it adds NO2 and not SO3H. Notice there is no answer where NO2 is para. If there was, the answer would be both of them.
yup, that's the only right answer choice. However, I had a question about this myself because I'm worried about getting tripped up on the DAT. Let's say it's just like yours, nitration of toluene and it's asking for the "major product(s)":
A) meta NO2
B) para NO2
C) ortho NO2
D) B and C
would the answer be just B or would it be D? I've seen several times that the para position is slightly favored over the ortho position, so is that the major product? Or does it want both?
In your case, it's the ortho NO2 because like ttpharm said, there's no para NO2 option.
I believe if you get a question on the DAT testing ortho vs. para position you will be given a group that is very sterricaly (sp) hindering like a tert butyl group and not just a methyl group. I don't think you will have to worry about the answer being too ambiguous.