An inline filter has an estimated life of 9 years. By adding a purifier to the filter, savings of \(\$ 300\) in annual operating costs can be obtained. Annual interest on capital is 8 percent. Compute the maximum expenditure justifiable for the purifier.

a. \(\$ 24\)

b. \(\$ 33\)

c. \(\$ 300\)

d. \(\$ 1,875\)