Calling ranges in BB against SB push

[pofigistka]

$50+5

Poker Stars
No Limit Holdem Tournament
Blinds: t200/t400
9 players

Relevant stack sizes:

SB: t3900
BB (hero): t3750

Pre-flop: (9 players) Folded round to SB who moves in. SB has played pretty tight for the first hour or so, but has become a lot more active since the antes have kicked in, and has pushed quite often from hijack/cutoff/button when folded to.

What do you do here as hero with:
1) A4o
2) KJs
3) 55


Does your answer differ if (a) SB starts the hand with t10,000, BB has t3750 (b) SB starts the hand with t3900, hero has t10,000

[AC-Cobra]

Has he been called and showndown on any of the pushes?

Can you give us a more exact stage of the tournament we're at?