Choose the correct preposition to complete the sentence: “All the efforts of the batsmen went ____ vain as the bowlers failed to perform well.”

Introduction / Context:
This question tests your knowledge of English idioms and correct preposition usage. The sentence describes a situation where the hard work of the batsmen produced no useful result because the bowlers did not perform. The key phrase here is a fixed idiom, and you must know which preposition correctly completes the expression to make the sentence grammatically and idiomatically correct.

Given Data / Assumptions:

• Sentence: “All the efforts of the batsmen went ____ vain as the bowlers failed to perform well.”
• Options: for, off, in, out, at.
• We assume standard modern English idiomatic usage.

Concept / Approach:
The commonly used idiom in English is “to go in vain”, which means that all the effort or action produced no effective result. Therefore, the preposition that normally appears before “vain” in this expression is “in”. The task is to recognise this fixed phrase and select the correct preposition, not to interpret the sentence word by word in a literal way.

Step-by-Step Solution:

Step 1: Read the sentence carefully and focus on the phrase involving “vain”. Step 2: Recall standard idioms. English uses “in vain” to mean “without success” or “without producing the desired result.” Step 3: Test the options in the blank. “Went for vain”, “went off vain”, “went out vain”, and “went at vain” all sound ungrammatical and unfamiliar. Step 4: Insert “in”: “All the efforts of the batsmen went in vain” sounds natural and matches the known idiom. Step 5: Confirm that this also fits the context, in which the batsmen's hard work did not lead to a win due to weak bowling.

Verification / Alternative check:
You can verify by thinking of other sentences that use this phrase, such as “All his attempts were in vain” or “They searched in vain for the missing file.” In each case, “in vain” means that the efforts did not succeed. Replacing “in” with any other preposition breaks the natural flow and produces incorrect English, which confirms that “in” is the only correct answer here.

Why Other Options Are Wrong:
“For vain”, “off vain”, “out vain”, and “at vain” are not recognised idiomatic combinations in English. They do not form a standard phrase and therefore make the sentence sound wrong. Even if a reader could guess the meaning from context, examinations test accepted idiomatic usage rather than creative expressions, so only “in” is acceptable.

Common Pitfalls:
Some learners may overthink the meaning of “for” and try to construct “went for vain” based on literal logic, but idiomatic phrases must be learned as set combinations. Others might be confused by similar sounding expressions like “for nothing” and mix them up. The best way to avoid such mistakes is to read widely, notice fixed patterns like “in vain”, and memorise them as standard units of language.

Final Answer:
The correct preposition is in, giving the idiomatic expression “went in vain.”