$22 - How do you play KK with a flopped A?

[splashpot]

Party Poker No-Limit Hold'em Tourney, Big Blind is t15 (10 handed) FTR converter on zerodivide.cx

MP1 (t745)
MP2 (t770)
MP3 (t800)
CO (t920)
Hero (t775)
SB (t980)
BB (t785)
UTG (t640)
UTG+1 (t785)
UTG+2 (t800)

Preflop: Hero is Button with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">MP1 raises to t50</font>, <font color="#666666">2 folds</font>, CO calls t50, <font color="#CC3333">Hero raises to t200</font>, <font color="#666666">2 folds</font>, MP1 calls t150, CO folds.

Flop: (t472.50) 2[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets t45</font>, Hero ??