Opener's Rebid after Partner's Negative Double 3

Opener's Rebid after Partner's Negative Double 3

Question:

You are South. Matchpoints. None vul. 

You hold: 

AQ87
A2
KQ1087
KJ

What is your next call on this auction:

  West    North    East    South  
   1diamonds icon
1hearts iconDbl Pass?

Answer: