Final answer:
If an inscribed angle of a circle intercepts a semicircle, then the angle is a right angle (B).
Step-by-step explanation:
An inscribed angle is an angle formed by two chords in a circle, where the vertex of the angle is on the circle and the sides of the angle intersect the circle. If an inscribed angle of a circle intercepts a semicircle, then the angle is a right angle (B). A right angle is equal to 90 degrees. This is because a semicircle is exactly half of a circle, so the central angle that intercepts a semicircle is 180 degrees, and since the inscribed angle is half of the central angle, it is 90 degrees.