Step 1: Understanding the Concept:
This question tests "Antonyms," which are words with opposite meanings.
The word in question is "Loquacious."
Linguistically, the root "loqu" or "loc" means "to speak" (as in ventriloquist, soliloquy, or colloquial).
The suffix "-ous" means "full of."
Therefore, a loquacious person is literally "full of speech" or extremely talkative.
Step 2: Detailed Explanation:
To find the antonym, we need a word that describes someone who speaks very little or is silent.
1. Evaluation of Options:
(C) Taciturn: This is the correct antonym. 'Taciturn' describes a person who is habitually reserved or uncommunicative in speech. They are the exact opposite of someone who is loquacious.
Example: "While the host was loquacious, his wife was quiet and taciturn."
(A) Talkative: This is a direct synonym. Using this would mean the same thing as the original word.
(B) Garrulous: This is a near-synonym. It describes someone who is excessively talkative, especially on trivial matters. It often has a more negative connotation than loquacious.
(D) Verbose: This is also related to being talkative, but specifically refers to using more words than are necessary in writing or speaking. A verbose person might not talk a lot, but when they do, they use too many words.
2. Deep Dive into 'Taciturn':
The word 'Taciturn' comes from the Latin 'tacere' (to be silent). This same root gives us 'tacit' (understood without being said).
A taciturn person doesn't just happen to be quiet at the moment; it is a part of their temperament to avoid speaking unless necessary.
3. Comparing the 'Talkative' Spectrum:
Loquacious / Garrulous / Talkative $\leftarrow$ OPPOSITES $\rightarrow$ Taciturn / Reticent / Silent.
Step 3: Final Answer:
Since "Loquacious" means talkative and "Taciturn" means reserved in speech, they are antonyms. Therefore, Option (C) is the correct answer.