None of us knew the way.
The correct tag-question for the sentence above is __________.

The correct answer is Option A (did we ?).

Key Points:
• This question evaluates the candidate's understanding of Question Tags, a fundamental grammatical concept frequently tested in MPSC and other competitive examinations. Grasping the correct polarity and pronoun usage is essential for mastering this topic.
• Option 1 is the correct answer according to the official MPSC answer key. The underlying rule states that a sentence with a negative subject or meaning requires a positive question tag. 'None' is a negative word, making the statement negative.
• Let us analyze why the other options are grammatically incorrect. The verb 'knew' is in the simple past tense, so the auxiliary verb must be 'did'. Since the main clause is negative ('None'), the tag must be positive ('did'). The subject 'us' changes to the subject pronoun 'we' in the tag. Option 3 ('didn't we?') is incorrect because it uses a negative tag for a negative sentence. Options 2 and 4 incorrectly use the object pronoun 'us' instead of 'we'.
• A common MPSC trap is overlooking negative words like 'none', 'hardly', or 'scarcely', leading students to mistakenly use a negative tag.
• Always check the sentence's overall polarity before formulating the question tag.
• Key Takeaway: Remember: Negative statements (using words like none, nobody, hardly) always take a positive question tag.