Choose the correct sentence .
AIt is high time he improved his behaviour.
BIt is high time he will improve his behaviour.
CIt is high time he improves his behaviour.
DIt was high time he will improve his behaviour.
AIt is high time he improved his behaviour.
BIt is high time he will improve his behaviour.
CIt is high time he improves his behaviour.
DIt was high time he will improve his behaviour.