Sentence Correction (SC) | Re: *700* Biologists believe that they have found one

Biologists believe that they have found one of the substances thattell individual genes both when to become active and when to remain quiescent in the earliest phases of an embryo’s development.

(A) tell individual genes both when to become active and when to remain

(B) tell individual genes both at which time they should become active or should remain

(C) tells individual genes both when to become active or remain

(D) tells individual genes both when to become active or when to remain

(E)