The amount of fertilizer in a landscaping company’s warehouse decreases at a rate of 3% per week. The amount of fertilizer in the warehouse was originally 78,000 cubic yards. Which function models the amount of fertilizer in cubic yards left w weeks?

a. f(w) = 0.97(78,000)w
b. f(w) = 78,000(1.03)w
c. f(w) = 1.03(78,000)w
d. f(w) = 78,000(0.97)w