Help with Final Table hand On Mansion

[Sandrine]

Hello,

Here's a hand I played yesterday (not able to get the real HH so no converter):

Blinds 3000-6000 ante 300

Approx. Stacks with 7 players left on final table

UTG 140 000
UTG + 1 to cutoff have between 50 and 80K
Button (Me) 110 000
SB: 65 000
BB: 55 000

Prize pool:

1st: 24000
2nd: 15000
3rd: 10900
4th: 7000 5th: 4600
6th: 3400
7th: 2400

UTg had been aggressive in the past, but since his chip lead got reduced, he had been pretty passive lately

The hand:

UTG raise to 18 000

All fold to me on the button;

I have KK

Whats my move?

Thanks for your help!

Sandrine