Answer:
A. (first choice)
Step-by-step explanation:
Examine all options:
A. The diagram shows the arc (1/4 from a circle). While rotating this arc about the given axis, we get the hemisphere.
B. The diagram shows the semicircle (1/2 from a circle). While rotating this semicircle about the given axis, we get the whole sphere.
C. The diagram shows the segment (perpendicular to the axis). While rotating this segment about the given axis, we get the circle (lying in a plane).
D. The diagram shows the segment. While rotating this segment about the given axis, we get the cone.
