Nice question. One thing would have made it harder: having a fake string conversion error as an option. Honestly, I did not know that LEFT does an implicit conversion, but because there was no error as a choice, I figured it would convert correctly and then was able to work out the right - or should I say correct - answer.
So I'm happy that I got the correct answer, but I'm not happy that I didn't know about the implicit conversion. I suppose I should be happy, though, because that means that there is always more to learn with SQL Server! :w00t: