Ah, I see. I suppose they want to know whether you applied to Cambridge, to be honest. They also ask for other Oxbridge tests like the TMUA. I don't know whether that's viewed favourably or negatively but I'd answer truthfully as you are planning to meet that offer. Anyways, they do say they won't disadvantage you if you are applying to Oxbridge, I'm presuming it has more to do with logistics, as in how many applicants they would need to send offers to as many of them may end up getting into Oxbridge?