Which expression represents the volume, in cubic units, of the composite figure?
A
2 4 thirds pi open paren 20 cubed close paren plus pi open paren 20 squared close paren 28B
2 4 thirds pi open paren 10 cubed close paren plus pi open paren 10 squared close paren 28C
4 thirds times pi times open paren 10 cubed close paren plus pi open paren 10 squared close paren 28D
4 thirds times pi times open paren 20 cubed close paren plus pi open paren 20 squared close paren 28