Sentence improvement — Fix the idiom ‘‘(none) the wiser’’ in ‘‘We were not the wiser for all this effort to explain the case to us.’’ Select the word that completes the standard expression.

Given sentence
We were not the wiser for all this effort to explain the case to us.

Concept/Approach
The fixed idiom is ‘‘none the wiser’’ meaning ‘‘no better informed’’ despite explanations or efforts.

Option analysis
A: none — Yields the idiom: ‘‘We were none the wiser ...’’B: neither — Not used in this idiom.C: nevertheless — An adverb; does not fit the construction.D: No improvement — Leaves a non-idiomatic structure.

Common pitfalls
Substituting ‘‘not’’ in place of the fixed collocation ‘‘none the’’ breaks the idiom and sounds unnatural.

Final Answer
none