A single, in-depth work on a single subject published as a standalone book is called a

• A. Monograph
• B. Periodical
• C. Atlas
• D. Handbook

Answer: (A)

The main idea being tested is recognizing a publication that presents a detailed, in-depth study of one subject in a single, standalone book. A monograph fits this exactly: it is a thorough, focused treatment of a single topic, usually written by one author or a small group and published as one complete book rather than as part of a series of journal issues.

This differs from a periodical, which is a serial publication issued in multiple issues (like journals or magazines) and often covers a range of topics rather than a single, deep dive. It also differs from an atlas, which is a reference book composed mainly of maps. And it differs from a handbook, which is typically a practical, concise guide aimed at quick use for specific tasks, not an exhaustive study of one subject.