A store had 250 bottles of water. Each week, 40% of the bottles were sold and 48 new bottles arrived in shipments. Which recursive function best represents the number of bottles of water in the store?

a. f(n ) = f(n - 1) • 0.4 + 48, n > 0.
b. f(n ) = 250 - f(n - 1) • 0.4 + 48, n > 0.
c. f(n ) = f(n - 1) • 0.6 + 48, n > 0.
d. f(n ) = 250 - f(n - 1) • 0.6 + 48, n > 0.