In the following question, select the alternative which best expresses the meaning of the given idiom or phrase: A wild goose chase.

Introduction / Context:
This idiom question tests your knowledge of fixed English expressions whose meanings cannot be guessed directly from the individual words. The phrase a wild goose chase is a colourful metaphor, and you must know its established meaning, which is very common in spoken and written English. Such idioms often appear in reading comprehension and listening sections as well.

Given Data / Assumptions:
Idiom: A wild goose chase.
Options: Fruitful search, Timely search, Useless search, Wrong decision.
You must choose the option that best captures the meaning of the idiom as a whole.
We assume the idiom is used in sentences like We were on a wild goose chase all day.

Concept / Approach:
Literally, chasing a wild goose would be nearly impossible and pointless, because wild geese are hard to catch and unpredictable. Over time, the idiom a wild goose chase has come to mean a hopeless or futile search, a pursuit that is unlikely to succeed and wastes time and effort. The key idea is uselessness or futility, not being fruitful or timely. Therefore, the best match is useless search.

Step-by-Step Solution:
Step 1: Recall the figurative meaning of a wild goose chase from common usage: a long and pointless search or pursuit. Step 2: Examine Fruitful search. Fruitful means productive or successful, which is the opposite of what a wild goose chase suggests. Step 3: Examine Timely search. Timely simply means done at the right time; the idiom does not comment on timing but on the result and usefulness. Step 4: Examine Useless search. Useless directly conveys the idea of being pointless, with no effective result, which matches the idiom perfectly. Step 5: Examine Wrong decision. A wild goose chase may be caused by a wrong decision, but the phrase itself describes the nature of the search, not the correctness of the initial decision. Step 6: Therefore, the correct explanation of the idiom is Useless search.

Verification / Alternative check:
Consider an example: The address he gave me was wrong, so my entire trip across the city turned out to be a wild goose chase. Here, the speaker means that the effort and search were wasted and did not lead to the desired result. Replacing a wild goose chase with a useless search keeps the meaning intact, confirming the choice. Trying fruitful search or timely search would contradict the speaker's frustration.

Why Other Options Are Wrong:
Fruitful search suggests a successful outcome with good results, which is completely opposite to the feeling of frustration implied by a wild goose chase.
Timely search focuses on when the search was conducted, not on whether it was effective or pointless.
Wrong decision describes a choice, not a search; while wrong decisions may lead to wild goose chases, the idiom itself labels the search, not the decision.

Common Pitfalls:
Students sometimes overthink idioms and look for highly abstract answers. In many exam questions, the simplest paraphrase is the correct one. Another common error is to focus on just one word, such as chase, and assume it means any search, ignoring the crucial modifier wild goose. Remember that the whole phrase must be taken together, and its established usage in real language should guide your choice.

Final Answer:
The idiom A wild goose chase means a useless search (option C).