Choose the best answer

1 there were no chairs __ on , so we all had to sit on the floor
A sists
B to sit
C sitting
D sat

2 she was a key _ in the reorganization of the health service 
A play
B player
C playable
D playful

3 i think we cannot find places in a big city that __ the country 
A so quiet as
B as quiet as
C more as more quiet
D as and as quiet

4 let's go by bus . it's
A much cheaper
B more cheaper
C much cheaper than 
D more cheaper than