Correct Answer: Drab

Solution : The correct choice is the second option .

Explanation:

Jejune is an adjective used to describe something that is dull, lacking interest, or insipid. It often refers to ideas, writing, or things that are simplistic and unstimulating.

Drab is a fitting synonym in this context. It denotes something dull, lacking brightness or interest.

The meaning of the other options are as follows:

• Poignant means evoking a keen sense of sadness or regret.
• Unchildlike focuses on the absence of childlike qualities.
• Cosmopolitan refers to someone or something that is sophisticated, worldly, or global.