Which of the following best describes a claim supported by reasons?

A claim supported by reasons is accurately described as an argument. In the context of advocacy and debate, an argument is structured by presenting a central claim or assertion that is bolstered by reasoning and evidence. This foundational structure allows for the claim to be persuasive and logical, providing the basis for discussion or debate on a particular issue.

Unlike advocacy, which refers more broadly to the act of supporting or promoting a cause or policy, an argument specifically focuses on the logical connection between a claim and its supporting reasons. Public discourse involves the exchange of ideas and viewpoints in a public setting, often incorporating various arguments, but itself does not denote this specific structure of claim and reasoning. Power, while it can influence arguments and advocacy, does not pertain to the logical framework necessary for the construction of claims supported by reasons.

Thus, the term "argument" clearly encapsulates the essence of a claim underpinned by logical reasoning, making it the most accurate choice among the options provided.