Two hamburger restaurants are located at opposite ends of a north-south shopping mall. From end to end, the shopping mall is 1/2 mile in length. Restaurant North and restaurant South each sell hamburgers for $5.00. A shopper incurs $0.10 per 1/8 mile in travel costs. Shoppers who plan to eat hamburgers are uniformly distributed around the shopping mall. Suppose that restaurant North lowers the price of its hamburgers to $4.90. Suppose that restaurant North raises the price of its hamburgers to $5.10. Other things being equal, how many shoppers will eat at North?
a. 37.5 percent
b. 28 percent
c. 31 percent
d. 44 percent
e. 32.5 percent