A travel agency will plan a tour for groups of size 53 or larger. If the group contains exactly 53 people, the price is $800 per person. However, each person's price is reduced by $10 for each additional person above the 53. If the travel agency incurs a price of $150 per person for the tour, what size group will give the agency the maximum profit? a. 6 b. 32 c. 70 d. 91 e. 59