calculate
cylinder=height times pi times r^2
sphere=4/3 times pi times r^3
cone=1/3 times pi times r^2 times hdight
cylinder=15 times pi times 5^2=375pi
sphere=4/3 times pi times 6^3=288pi
cone=1/3 times pi times 8^2 times 15=320
375 is the greatest so the answer is A a cylinder