1. Big blind has any set because he would have had the odds to call preflop.
2. UTG is either AsJs, AsQs, or AsKs. (KK or AA possible)
3. MP3 has JJ, KK, or AA.
4. HERO should fold because he doesn't have the odds to draw to one out. There is a good chance that UTG has a big spade draw which makes folding the right place.