Concept:The phrase “none the wiser” is a fixed idiom that means not gaining any knowledge or understanding despite an explanation.
Explanation:The sentence says, “Even after his explanations, I was none the ___________.”
This situation requires the idiom “none the wiser.”
Here, “wiser” is the comparative form of “wise,” and it fits perfectly after “none the.”
The speaker means that after hearing all the explanations, they still did not understand any better.
Option B, “wise,” is the base form and does not complete the idiom.
Option C, “wisest,” is the superlative form and does not suit the comparative structure.
Option D, “worse,” has a completely different meaning and makes the sentence illogical.
Only option A gives the correct idiomatic and grammatical meaning.
Answer:Option A: wiser.