Identify the segment in the sentence which contains a grammatical error.
Let us work out the details of our endeavour, shouldn’t we?

Correct option is A

The correct answer is (a) shouldn’t we.
Explanation: The error lies in the tag question "shouldn’t we." When using a question tag with an imperative sentence beginning with "Let us" or "Let's," the correct tag should be "shall we" instead of "shouldn’t we." The phrase "shouldn’t we" would not be appropriate in this context.
Correct Sentence: Let us work out the details of our endeavour, shall we?
Grammatical rule used: Imperative sentences with "Let us" or "Let's" typically use "shall we" as the tag question.
Example: Let's go for a walk, shall we?