Acompany that manufactures storage bins for grains made a drawing of a silo. the silo has a conical base, as shown below:

which of the following could be used to calculate the total volume of grains that can be stored in the silo?

a) π(2ft)2(10ft) + one over threeπ(13ft − 10ft)2(2ft)
b) π(10ft)2(2ft) + one over threeπ(13ft − 10ft)2(2ft)
c) π(2ft)2(10ft) + one over threeπ(2ft)2(13ft − 10ft)
d) π(10ft)2(2ft) + one over threeπ(2ft)2(13ft − 10ft)