Which term best fits 'the set of grammar rules used in writing'?

• A. Conventions
• B. Compose
• C. Compare
• D. Credible

Answer: (A)

The main idea here is identifying the word that names the rules used in writing. Conventions describes the standard rules and norms writers follow—grammar, punctuation, spelling, and formatting—so it fits the phrase “the set of grammar rules used in writing.” The other options describe actions or qualities rather than a set of rules: to compose is what you do when you write, to compare is to examine similarities and differences, and credible describes something trustworthy. So conventions is the best match because it names the system of accepted writing rules that guide clear communication.