单选题 Psychologists have errantly mounted an offensive against what they describe as nastiness to ward students by educators.
A. arbitrariness B. unpleasantness C. severity D. aloofness

【正确答案】 B
【答案解析】arbitrariness霸道，恣意。unpleasantness煞风景的事，不愉快的事。severity严肃，严格。aloofness超然的态度。nastiness污秽，不洁。