担任行政职务的人民警察实行职务等级编制警衔，采取一职一衔、职衔不交叉的办法。( )

— Do you know where David is ? I couldn’t find him anywhere.

— Well. He ______ have gone far –his coat’s still here.

A．shouldn’t

B．mustn’t

C．can’t

D．wouldn’t