og-94中的itself

94. The psychologist William James believed that facial expressions not only provide a visible sign of an emotion, actually contributing to the feeling itself.

(A)  emotion, actually contributing to the feeling itself

(B)  emotion but also actually contributing to the feeling itself

(C)  emotion but also actually contribute to the feeling itself

(D)  emotion; they also actually contribute to the feeling of it

(E)   emotion; the feeling itself is also actually contributed to by them

选C,请问其中的itself指代什么?

既然是反身代词是不是一定一定指的是动作的执行者?但是那样的话就指expressions了,单复数不一致,应该不对的.那么这里的itself究竟指什么呢?请赐教