Use Vectors to Find the Measure of the Angle at Vertex

Multiple Choice

Use vectors to find the measure of the angle at vertex B of triangle ABC, when $A = ( 5,4 )$ , $B = ( - 2,4 )$ , and $C = ( - 3 , - 4 )$ .Round answer to two decimal places.

A) 95.94°
B) 98.47°
C) 97.13°
D) 95.04°
E) 99.65°