Answer:
By destroying his artwork before it was sold, Banksy played a prank on the artworld that mocked the price of art.
Explanation:
1. Important
2. Right
3. Racist
4. Cruel
5. Good
"A" is probably the best choice. All of your other choices are close-ended questions, and can only be answered with a simple yes or no, But "A" is an open-ended question because the answer wont be just a "yes" or "no".
Hope this helps!