Which composite function can be used to find the new profit formula after the increase in the number of units?
a. p(d) = –7.5d² + 600d – 2,000
b. p(d) = –3.75d² + 600d – 2,000
c. p(d) = –22.5d² + 1,800d – 2,000
d. p(d) = –33.75d² + 1,800d – 2,000