I'm pretty sure it's answer D. It's the only answer choice that really makes sense.
Answer:
The correct answer is option B. "12 hours".
Explanation:
The process of mitosis in mouse fibroblast cells have been studied and characterized for researches purposes. Therefore, it is possible to predict that it will take around 12 hours for mouse fibroblast cells to begin the process of sister chromatids separation after finishing growing its organelles and synthesizing proteins. If the process takes less time than 12 hours will indicate a premature sister chromatid separation, and that something has caused down regulation or inhibition the histonedeacetylase (HDAC) activity.
I think it might be the first one: hiv infections. (hope this helps!)
The answer is C because the key is “group that live in the same area”