Any Ideas?

You are South and dealer at match points. NS vul.
The bidding has been:

SouthWestNorthEast
1Pass2Pass
2Pass4Pass
PassPass

West starts with two top diamonds, the ace and king (East following with the 2 and 3 (standard signals). Then West shifts to the five of hearts. How would you continue from there, here is the layout of your hand and dummy.

Dummy (North)

K94
KQJT3
J4
K32

You (South)

QT853
A7
QT
AJ86

Any ideas to me please --- villyn@xtra.co.nz