His visit to London last spring is ( ) as a great success.

His visit to London last spring is ( ) as a great success.
A、looked into
B、looked to
C、looked over
D、looked upon
【正确答案】：D
【题目解析】：look upon 把…看成…，句子含义为去年他对伦敦的访问看成是一种成功。