the answer is A. because if you look at the answers none of then contributes to being open except A.
<span>It was the first step to connecting the western and eastern hemispheres together through trade and culture exchange. Although European diseases wiped out many native cultures, other exchanges such as corn and potatoes allowed a better diet for people and increased native and Irish population.</span>
Answer: Battle of the somme
Explanation:
A generally accepted fact does not have to be cited in an academic paper, whereas a paraphrase, another person's opinion, and a diagram have to be cited.