Answer:
A
Explanation:
"Keep", "factor", and "calculate" are all verbs in the list of things the new system allows teachers to do. The other sentences are inconsistent with their list of verbs/adjectives/nouns. Thus, option A is the only one that is grammatically correct.
Pardon my french to us, is normally just used to apologize for using profanity.
I wish I could explain why, but I honestly have no idea.
Hope this helps though!
