Sunday Warmup 99 hand

[AragornX151]

I always find myself struggling with the right move 77-TT in these spots, given stack sizes. What's the best play? The opener has raised about once an orbit, also seems to like low aces, no super-duper reads.

PokerStars No-Limit Hold'em Tourney, Big Blind is t600 (9 handed) internettexasholdem.com

Button (t10050)
SB (t16525)
BB (t13500)
UTG (t9675)
UTG+1 (t21400)
MP1 (t10075)
MP2 (t5950)
MP3 (t43075)
Hero (t11350)

Preflop: Hero is CO with :9s, :9c.
[color=#666666]2 folds</font>, [color=#CC3333]MP1 raises to t1500</font>, hero?