Concept:A tag question is a short question added to the end of a statement to confirm or check information.
The tag must match the main clause’s auxiliary verb and subject, and its polarity (positive/negative) must be opposite to the statement.
Explanation:The main statement is “We were lucky...”, which is positive.
The auxiliary verb in the main clause is “were”, and the subject is “we”.
Therefore, the tag must be negative: “weren't we?”
The clause “our driver didn't die” is a minor detail inside the sentence, so it does not determine the tag.
Options A and C use “did”, which is wrong because the main verb is “were”, not “did”.
Option B, “isn't it”, is also wrong because the subject is “we”, not “it”.
Only option D gives the correct negative tag for a positive statement with “were” and “we”.
Answer:D. weren't we