Rent Expense on the Factory Building of $100,000 Is Allocated

Rent Expense on the Factory Building of $100,000 is allocated to three departments.The cost-allocation base for this expense is number of square feet,which equals 50,000 square feet.Information for the three departments housed in the factory building are as follows:
$\begin{array}{lll} \text {Department }& \text { Square Feet}& \text { Cubic Feet}\\\text { Department A } & 15,000 & 15,000 \\\text { Department B } & 5,000 & 5,000 \\\text { Department C } & 30,000 & 20,000 \\\end{array}$
How much Rent Expense is allocated to the three departments?
$\begin{array}{lll}&\text { Department A }&\text { Department B }&\text { Department C }\\A)&\$ 15,000 & \$ 5,000 & \$ 30,000 \\B)&\$ 37,500 & \$ 12,500 & \$ 50,000 \\C)&\$ 30,000 & \$ 10,000 & \$ 60,000\end{array}$
D) none of the above