Which single factor is tended to have been considered by the author as the most important in the development of man

A．He majors in engineering.
B．He wasn’t at the lecture at that time.
C．He has only recently become interested in philosophy.
D．He thinks the woman should also attend Prof. Warner’s class.

A．He was annoyed.
B．He was pleased.
C．He felt it could be replaced.
D．He did not care.