Concept:A tag question is a short question added to the end of a statement to confirm or check information. The tag uses the same auxiliary verb and the opposite polarity of the main statement.
Explanation:The main statement is positive: "We were lucky."
The main auxiliary verb is "were" because the sentence begins with "We were lucky."
A positive statement needs a negative tag, so the tag should contain "weren't".
The subject in the tag must match the subject of the main statement, which is "we".
Therefore, the correct tag is "weren't we".
The phrase "didn't die" is inside the subordinate clause, so it does not determine the auxiliary in the tag.
Options B, C, and D do not match the subject and auxiliary correctly.
Answer:A. weren't we