Step 1: Understanding the context.
The sentence contrasts two opposite qualities of the same person — “wise” and “timid.” Hence, a conjunction expressing contrast is needed.
Step 2: Analyze the given options.
- (a) an: Incorrect, as it is an article used before vowel sounds, not suitable here.
- (b) yet: Correct, it is a conjunction meaning “but at the same time,” used to show contrast.
- (c) but: Grammatically possible but less elegant than “yet” in this context; “yet” gives smoother contrast.
- (d) however: Requires punctuation or a semicolon before it, so it’s not the correct choice for this simple sentence.
Step 3: Meaning check.
The sentence “She is wise yet timid” means that although she is intelligent and sensible, she is also shy — expressing contrast.
Step 4: Conclusion.
Hence, the correct answer is (b) yet.