Which phrase is an example of metonymy?

Metonymy is a figure of speech in which one word or phrase is substituted for another with which it is closely associated. In the phrase "All hands on deck," the term "hands" does not refer to the literal body parts but rather to the sailors or crew members who are available to help with the tasks on a ship. This use of "hands" represents the people who possess those hands, illustrating how metonymy operates by using part of something to signify the whole.

The other phrases provided showcase different figures of speech. For instance, "The pen is mightier than the sword" illustrates the contrast between written words (represented by the pen) and military force (represented by the sword), but this is more of a symbolic comparison rather than metonymy. "Let me give you a hand" suggests assistance or help but uses "hand" in a more idiomatic sense rather than as a stand-in for people. "A swelling of pride" conveys an emotion but does not fit the definition of metonymy because it does not involve a substitutive relationship based on an association. Each of these alternatives serves distinct purposes in language, but "All hands on deck" distinctly exemplifies the metonymic use by representing the crew with