The answer is D. 39 degrees. The area where b is shows an acute angle. The only answer shown with an acute angle is 39. 141 and 180 are obtuse angles, and 90 is a right angle.
A straight line will have a degree of 180 degrees. Since one side is given to you as 141 degrees, you will need to subtract that from 180. 180-141= 39 so angle b is 39 degrees
