单选题 According to the passage, Houston aimed his leg-islative challenge at the graduate and professional school level on the basis of the assumption that
【正确答案】 D
【答案解析】Houston believed that the battle had to begin at the graduate level "to mitigate fear" (relieve apprehension) of race mixing and miscegenation that might otherwise have caused the judges to rule against the NAACP-sponsored complaints.