A right circular cone has height 12 cm and radius 6 cm at its top. Water is poured in so that the depth h of the water increases at a constant 0.50 cm/s. When the water is 4 cm deep, what is the rate at which the water’s volume is increasing?
a) 4π cm3/s
b) 38π cm3/s
c) 2π cm3/s
d) 6π cm3/s