Answer:
GO (2009) concluded, "The rules and regulations clearly direct all in the business sector to observe social obligations and responsibilities" (p.67).
Explanation:
Hope it helps
The answer is D.
"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 D is the only one that is grammatically correct.
I am not too good at explaining, so let me know if you are still confused.
Hope this helps! :)