Sure I’ll fill in any blanks, but you didn’t show any pictures or a text?
The correct answer is A. they do not wish the soldiers to hear their discourse.
They are planning to kill Caesar, because they no longer think he is fit to rule the country. Thus, they move to a more secluded place to go over their plan, and they need to be alone so that the guards don't hear them and try to thwart their plan.
