The point O is the center of the circle circumscribed about \triangle A B C, with \angle B O C= 120^{\circ} and \angle A O B=140^{\circ}, as shown. What is the degree measure of \angle A B C ?

**Answer Choices**

A. 35

B. 40

C. 45

D. 50

E. 60

The point O is the center of the circle circumscribed about \triangle A B C, with \angle B O C= 120^{\circ} and \angle A O B=140^{\circ}, as shown. What is the degree measure of \angle A B C ?

**Answer Choices**

A. 35

B. 40

C. 45

D. 50

E. 60