Deferred Big 4 offer for 1 year, how do I answer question about full time offer?

I recently interned with a Big 4 firm this past summer in advisory. I accepted a full time offer; however, I deferred the start date for one year because I no longer want to graduate next June for various reasons (I would have graduated early in 3 years). I want to look for an internship for next summer because the Big 4 firm is not able to offer me another internship. The recruiters have specifically told me that I can intern wherever I want next summer. I am mostly looking into corporate finance roles as my background is in finance. So my question is: if the companies I network and interview with ask me about a full time offer from the big 4 firm, how do I answer? I feel that an honest answer might turn companies away because they might think I wouldn't be interested in a full time opportunity. But, if I lie and say I did not accept a full time offer, I'm scared this might bite me down the road and get me in trouble with campus career services. The truth is I would renege on the big 4 offer if I feel that the company I intern with next summer can offer me better career opportunties. Any advice is appreciated, thanks!