Answer & Explanation
A) Megasearch engine
A search engine is a information retrieval program that constantly collects information on the Web, following links in Web sites and reading Web pages. The search results are presented in a list format and are called as hits.
A metasearch engine is a search tool that uses another search engine's data to produce its own results from the Internet. These engines take input from a user and simultaneously send out queries to third party search engines for results. It searches other search engines rather than individual Web sites.
Examples of Metasearch engine includes - Dogpile, Zoo, Yabado, Metager, etc...