After driving to a riverfront parking lot, bob plans to run south along the river, turn around, and return to the parking lot, running north along the same path. after running 3.25 miles south, he decides to run for only 50 minutes more. if bob runs at a constant rate of 8 minutes per mile, how many miles farther south can he run and still be able to return to the parking lot in 50 minutes?

(a) 1.5
(b) 2.25
(c) 3.0
(d) 3.25
(e) 4.75