Answer:
B and D
Step-by-step explanation:
A 20 degree intercepted arc will correspond with two angles: the inscribed angle and the central angle.
The central angle always has the same degree measure as the intercepted arc, so we want a central angle with degree 20. So, that's B.
The inscribed angle is the angle whose vertex is on the circle, not the center. This angle always has half the measure of the intercepted arc, so we want an angle with degree 20/2 = 10. So, that's D.
Thus, the answers are B and D.
Hope this helps!