What Is the Main Purpose of the Briefs Filed by Both

What is the main purpose of the briefs filed by both parties for a case that will be heard by the Supreme Court?

A) to explain why the case is being appealed to a higher court
B) to argue why constitutional or federal statutory law favors their position
C) to gain the support of interest groups who can influence the Court's decision
D) to release the details of the case in simpler terms to the public