12. A high school principal wants to determine if students' mathematical reasoning ability has any impact on their membership in academic clubs at the school. Twenty students were selected and given a mathematical reasoning test, with scores ranging from o to 50 (higher scores indicate more mathematical reasoning ability). Students were motivated to do well on the test with a reward system. These same students' membership in academic clubs was verified. Identify the response variable. A. Mathematical reasoning ability B. The high school C. Mathematical reasoning test D. Membership in academic clubs