Have not been at the table long so no reads. I definitely was not expecting CO to be the one to 4-bet me. Do you call here?

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

BB ($5.65)
UTG ($10)
UTG+1 ($15.20)
MP1 ($17.95)
MP2 ($27.25)
CO ($32.10)
Button ($12.55)
Hero (SB) ($24.20)

Preflop: Hero is SB with K, A
UTG (poster) checks, 1 fold, MP1 bets $0.75, 1 fold, CO calls $0.75, 1 fold, Hero raises to $3.50, 2 folds, MP1 calls $2.75, CO raises to $32.10 (All-In), Hero ???