GAUSS7 2023 Problem 11

Past Contests GAUSS7 2023
1

In the diagram, B C D is a straight line segment. The measure of \angle A B C is

Image

Answer Choices
A. 35^{\circ}
B. 40^{\circ}
C. 60^{\circ}
D. 75^{\circ}
E. 45^{\circ}