A closed right circular cylinder must contain 1000 cm3 of liquid. The material for the lateral surface costs \0.05persquarecentimeter,andthematerialforthetopandbottomcosts0.08 per square centimeter. Let r be the radius, in centimeters, of the cylinder. Which of the following is closest to the value of r that minimizes the total material cost?
a) 3.7
b) 4.6
c) 5.5
d) 6.3