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 $A B C$ , when $A = ( 6,1 ) , B = ( - 1,3 )$ , and $C = ( - 4 , - 5 )$ . Round answer to two decimal places.

A) 92.52
B) 94.61°
C) 95.95
D) 93.42
E) 97.13°