I think the answer is A.
I hope that helps :)
Answer:
A.
Explanation:
The key word is simultaneously when it comes to parallel computing. Although the option <em>could </em>potentially be C, it's more likely to be A because it's "more right" in the words of my old English teacher. This is because A implies them working on it at the same time to reach the goal more effectively (another key word).
