90. Four positive point charges are arranged as shown in the accompanying diagram. The force between charges 1 and 3 is 6.0 N ; the force between charges 2 and 3 is 5.0 N ; and the force between charges 3 and 4 is 3.0 N . The magnitude of the total force on charge 3 is most nearly
(A) 6.3 N
(B) 8.0 N
(C) 11 N
(D) 14 N