According to my hamble knowledge, it's generally OK.
You can look up the following sentence in Official guide Page 696, Para 3: "B replaces child with children but otherwise fails to correct A's errors of structure and logic, and C corrects only the error created by occurring."
3. The airline industry is cutting its lowest discount fares more widely, more substantially, and earlier this year than it normally does at the end of the summer, a time during which travel usually decreases and the industry uses some lower fares for the attraction of passengers. (B) during which travel usually decreases and therefore the industry will use some lower fares for the attraction of (C) in which travel usually decreases and in which the industry therefore uses some lower fares attracting (D) when travel usually decreases and the industry uses some lower fares to attract (E) when travel usually decreases and therefore the industry will use lower fares for the attraction of