Two Rockets, a and B, Approach Each Other as Shown

Multiple Choice

Two rockets, A and B, approach each other as shown in the figure. A travels to the right at 0.7c while B travels to the left at 0.8c. Both speed measurements are made relative to an inertial observer.
-Determine the speed of A relative to B.

A) c
B) 0.96c
C) 0.92c
D) 0.89c
E) 0.86c