Which term describes a detailed study of a subject?

• A. A detailed study of a subject
• B. Research into/on
• C. A research sample
• D. A questionnaire

Answer: (B)

A detailed study of a subject is described in academic language as research into or research on that subject. The word “research” names the activity of systematic inquiry, not just the description of it. Saying “research into X” conveys that you are undertaking a focused, investigative process to learn more about X, gather evidence, and draw conclusions. The other options don’t fit this idea: “a detailed study of a subject” merely restates the description rather than naming the activity; a research sample is the subset of participants or data used in a study; a questionnaire is a data‑collection tool, not the study itself. So the best term is the one that denotes the act of studying something in depth.