Does the first question seem a bit much of a 'gotcha'? I was slightly annoyed I got it wrong despite being quite capable of working with posets. XD
I suppose the way it is asked is completely valid, and will drive home the fact that relations have to be reflexive and illustrates very well what would be necessary to get a valid order.
What are other people's thoughts?
(Maybe it will be better once it isn't the only question, nor the first?).