Good question.

That being said, I fail to understand what the purpose of the question was - to test whether or not the user notices the "UNION", or that TRUNCATE can actually participate in a transaction.

The fact that TRUNCATE can participate in a transaction is something that not many people know when asked to list down the differences between a DELETE and a TRUNCATE.

By mixing up the "UNION" test and the TRUNCATE test, the question does draw the attention of the reader away from the important concept.

All in all, good effort, but most people will continue to have the misconception that TRUNCATEs cannot participate in a transaction even after reading and answering correctly to this question.