Which one of the following sentences or phrases is most likely to be considered a cliché?

A. Are you a man or a moose?

B. How dead is a dead doornail?

C. Look before you leap.

D. When in doubt, pout.

The answer is probably C - look before you leap. A cliche is an overused expression, usually an idiom that people tend to use too much. In writing, it is advised to avoid using such cliches. The remaining options aren't necessarily cliches, because they are not given in their original form, but are modified.