KK facing a big raise on a low flop.

[Eihli]

Opp is unknown.

Party Poker No-Limit Hold'em, $ BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($453.80)
BB ($544.80)
UTG ($367.60)
MP ($1283.74)
CO ($200)
Button ($195.10)

Preflop: Hero is SB with K, K. Hero posts a blind of $2. CO posts a blind of $6.
2 folds, CO (poster) checks, 1 fold, Hero (poster) raises to $14, BB calls $12, CO folds.

Flop: ($38) 3, 2, 5 (2 players)
Hero bets $30, BB raises to $141.85

So, think of a calling range preflop for him. 22-JJ, AT-AK
That's about it right? Of those, might he make this raise with any pair? If he has a pair between 66 and JJ he doesn't want to give a loan A a chance to outdraw him, but he also wants to be able to fold if he's pushed over. But is his raise too big to be that? If he has a set, there's no flush draw he'd need to charge and he really can't put me on an OESD so whyw ould he raise that big with a set?

All-in-all, I'm confused.