Provide an example of a question that could not be answered with a binary message. explain why this is the case, making reference to the definition of a binary message.

This is a question with a much simpler answer given its open ended ness - a representation merely means, given binary data, we can determine what 'thing' that binary data corresponds to.

That makes the question unanswerable, because words can all be represented in binary data, and the question cannot be answered without those. Thus, all answers we can convey have a binary representation of some form (that form being the translation of the words we used to communicate the answer into binary data).