The teacher, as well as all his students, ____ by the dancer’s p

The teacher, as well as all his students, ____ by the dancer’s performance. （QE05-04-42）
A、was impressed
B、had impressed
C、impressed
D、were impressed
【正确答案】：A
【题目解析】：本题考查的是主谓一致。主语应是teacher，动词用第三人称单数形式。as well as：都，这种句型根据as well as前的主语确定动词形式。