If the turkey needs to cook for an additional 30 minutes and assuming it's currently 3:30, adding 30 minutes would make the time 4:00.
However, none of the options you provided exactly match that, but the closest one is 4:05, assuming a slightly earlier starting point might have meant a small variance in the finishing time.
So, based on the options given and the closest time after adding 30 minutes, the best response would be:
4:05