What is a database?

• A. A research tool that contains organized information about related subjects
• B. A search engine that accesses results from multiple search engines
• C. A catalog showing the holdings of a digital or physical library
• D. A collection of online books in the public domain

Answer: (A)

A database is a structured, searchable collection of related information designed for efficient retrieval. This fits the idea of a research tool that contains organized information about related subjects, because databases store data in a way that lets you query multiple fields (like subject, author, date, keywords) to pull precisely the results you need.

Why the others don’t fit as well: a search engine gathers and returns results from many sources across the web, not a tightly organized, domain-specific store you query directly. A library catalog lists holdings—what a library has—rather than the content itself or a cohesive body of related information. A collection of online books in the public domain is typically a digital library or repository of items, not a structured database designed for complex, targeted searches across related subjects.