In no case（）give up the experiment. A. would he B. will he C. he will D. he would

The correct answer is B. will he.

Let’s break it down:

1. Structure of the sentence
The phrase “In no case” at the beginning of the sentence signals a negative or restrictive opening.
When a negative or restrictive phrase starts a sentence for emphasis, the sentence usually requires inversion (subject and auxiliary verb are switched).

2. Inversion rule
Correct form:

In no case will he give up the experiment.
Not:
In no case he will give up the experiment.

3. Tense
The sentence is a general strong statement about the future or his determination, so “will” fits better than “would” unless it’s clearly hypothetical or past context.

4. Looking at the options

A. would he → possible in a hypothetical context, but here simple future is more natural.

B. will he → correct inversion, correct tense.

C. he will → no inversion, wrong after “In no case”.

D. he would → no inversion, also wrong.

Thus the best choice is B. will he.

✅ Correct sentence:

In no case will he give up the experiment.