Some geometry problems i need some with!

when a 2-d circle is rotated around a line that it does not touch. what is the name of the resulting figure?

a. cavalieri section
b. torus
c. cross section
d. annulus

a sphere with radius 16 m is cut by a plane though it’s a great circle. what is the best description of the cross section that is shown?

a. a torus
b. a circle was radius 16 m
c. a circle with radius 8 m
d. a sphere with radius 8 m