The volume of a cone is given by the formula
... V = (1/3)π·r²·h
You have a radius of 4 cm and a height of 4·8 cm = 32 cm, so this becomes
... V = (1/3)π·(4 cm)²·(32 cm)
This seems to match your 3rd selection, ...
... one over three(3.14)(4cm)2(32cm)
