Select the option that can be used as a one-word substitute for the given…

One-word substitution questions test whether a single word carries the exact meaning of a longer descriptive phrase. Each candidate word has one fixed, dictionary-defined sense rooted in its origin, so the correct substitute must match the given phrase's meaning precisely, not merely share its general subject area.

The phrase “a person who has the ability to speak several languages” describes multilingual ability. The word formed from the Greek roots poly- (many) and glotta (tongue/language) denotes exactly a person who knows or can speak several languages, matching the phrase word for word.

Checking the remaining options against their own dictionary meanings confirms none of them fit:

• Coquette names a woman who flirts and trifles with men's affections without serious intent — a term about romantic behaviour, unrelated to language ability.

• Demagogue names a political leader who gains power by appealing to people's emotions and prejudices rather than reasoned argument — a term about political manipulation, not multilingualism.

• Almanac names an annual reference publication listing calendar dates, astronomical data, and other recurring information — an object, not a person or an ability.

Only the word built from “many languages” matches the given phrase, confirming it as the one-word substitute.