$29.$ Hannibal Company produces a number of chemical products, two of which are Product X$1$ and Product X$2.$ The controller and environmental manager have identified the following environmental activities and costs associated with the two products:

Product X$1$ Product X$2$

Pounds produced $400,0001,000,000$

Packaging materials $($pounds$)120,00060,000$

Energy usage $($kilowatt hours$)40,00020,000$

Toxic releases $($pounds into air$)100,00020,000$

Pollution control $($machine hours$)16,0004,000$

Costs of activities:

Using packaging materials $$360,000$

Using energy $96,000$

Releasing toxins $($fines$)48,000$

Operating pollution control equipment $112,000$

What is the energy usage cost per unit of Product X$2?$

a$.$ $$0\mathrm{.}096$

b$.$ $$0\mathrm{.}064$

c$.$ $$0\mathrm{.}032$

d$.$ $$0\mathrm{.}160$