B
Test analysis: Unrequited request: Unreasonable request (called a polite word when making a request, a self-effacing word). This is a case of inappropriate modesty. Craftsmanship: specifically refers to the ingenuity of man-made products rather than those made from nature, and describes the superb craftsmanship. Artificial is better than natural.
This is a misuse of objects. Teacher's mind for one's own use: describes being self-righteous, stubborn, and unwilling to accept the correct opinions of others. The literal meaning here is clear.