Answer: I would contend that the right answer is the A) It emphasizes the physical effort and skill in the creative process.
Explanation: Just to elaborate a little on the answer, it can also be added that the defining characteristic of craft is not the fact that it has a purpose or use, so option D can be discarded. In addition, although manual skill is often necessary to create crafts and/or to be occupied on a craft, and crafts often serve a practical function, those are not the defining characteristics either, so option C can also be discarded. A craft can be considered the creative expression of an idea in a specific form, but a painting or a novel can be defined as such as well, so that option can be discarded too. A craft primarily reveals the strength and skill (that's indeed the original meaning of the word) that have been invested in the creative process.