In Bush, Saddam was up ...... more than his match.

Solution (By Examveda Team)

In Bush, Saddam was up against more than his match.
In this context, the phrase "up against" means in competition or conflict with someone or something. The sentence suggests that Saddam was facing a formidable opponent or challenge in Bush. Therefore, "against" is the most appropriate choice to complete the sentence, conveying the idea of opposition or confrontation.