The volume of right circular cylinder A is given by the expression πr2h, where r is the radius of its circular base and h is its height. The volume of a cylinder with twice the radius and half the height of cylinder A is given by π(2r)2(
1
2
)h, which is equivalent to 4πr2(
1
2
)h=2πr2h.Therefore, the volume is twice the volume of cylinder A, or 2×22=44. Choice A is incorrect and likely results from not multiplying the radius of cylinder A by 2. Choice B is incorrect and likely results from not squaring the 2 in 2r when applying the volume formula. Choice D is incorrect and likely results from a conceptual error.