Correct Answer:
A. Serious
The question asks for the antonym of JOCOSE, which means playful or humorous. It describes someone who is fond of joking.
- Serious is the correct answer because it means solemn or grave in manner or disposition, directly contrasting with being playful or humorous.
- Playful is incorrect as it is a synonym of jocose, meaning full of fun and high spirits.
- Happy is incorrect because while a jocose person might be happy, 'happy' describes a state of mind, not the direct opposite of being humorous or joking. A serious person can also be happy.
- Frivolous is incorrect as it means not having any serious purpose or value, or being lighthearted. This is closer in meaning to jocose rather than its antonym.
Thus, 'Serious' best represents the opposite of being jocose, emphasizing a lack of playfulness or humor.