The correct option is C emotion but also actually contribute to the feeling itself
This sentence should depend on the correlative construction not only . . . but also y, where x and y are paraIlel. However, the faulty construction in the original sentence does not properly include the second element, but also, and so produces a sentence fragment. James says that facial expressions have two effects: they provide a sign of emotion and they contribute to emotion. Thus, in this sentence, not only should be followed by (x) provide a visible sign of an emotion, and but also should be followed by (y) actually contribute to the feeling itself.
(A) the not only. . . but also construction is violated, creating a sentence fragment.
(B) But also actually contributing is not parallel to not only provide; because contributing is a participle and not a verb, the result is a sentence fragment.
(C) Correct. The not only . . . but also construction is parallel, resulting in a complete sentence.
(D) The not only construction needs to be completed with but also and should not be interrupted by a semicolon. The feeling of it is awkward and wordy.
The correct answer is C.