Explanation:

This question asks for the correct definition of the word 'Polyglot'. This is a vocabulary question testing knowledge of specific English terms, often derived from Greek or Latin roots. **Etymology and Definition of 'Polyglot':** The word 'polyglot' comes from Greek: 'poly-' meaning 'many' and 'glotta' (or 'glossa') meaning 'tongue' or 'language'. Therefore, a polyglot is literally someone who speaks many languages. Let's analyze each option: **Option (A): the person who keeps many wives.** This describes a 'polygamist'. 'Polygamy' is the practice of having more than one spouse. This is distinct from speaking multiple languages. Therefore, this option is incorrect. **Option (B): the person who has command over many languages.** This is the precise and correct definition of a 'polyglot'. A polyglot is an individual who can speak or understand several languages, often with a high degree of fluency. This aligns perfectly with the etymological roots of the word. Therefore, this option is correct. **Option (C): the person who eats both vegetarian and non-vegetarian food.** This describes an 'omnivore'. 'Omnivore' refers to an animal or person that eats food of both plant and animal origin. This is unrelated to language ability. Therefore, this option is incorrect. **Option (D): the person who keeps spreading rumours.** This describes a 'rumormonger', 'gossipmonger', or 'propagandist'. Such a person is involved in disseminating unverified information or gossip. This has no connection to language proficiency. Therefore, this option is incorrect. **Conclusion:** Based on the etymology and standard definition, a 'polyglot' is a person who is proficient in multiple languages. Option (B) accurately provides this definition. Therefore, option (B) is the correct answer.