In writing, what supports a claim by providing factual backing?

The correct answer is evidence. In writing, evidence serves as the foundational support for a claim, lending credibility and substantiation to the argument being made. It consists of factual information, such as data, statistics, research findings, or documented testimonies, which bolster the assertion and help persuade the reader. By presenting evidence, the writer ensures that their claims are not merely opinions but are grounded in verifiable facts.

Anecdotes, while they can illustrate a point or provide a narrative context, do not provide the factual backing that is necessary to support a claim in a rigorous way. Observations may also provide insights or illustrations, but they can be subjective and may not constitute evidence in a more formal sense. Arguments are broader in scope and involve presenting reasons for a claim, but they depend on underlying evidence to be truly persuasive. Thus, evidence is the most effective tool for providing the necessary support for a claim in writing.