What is the solution

options:
a. (-2,-2)
b. (-1,-5)
c. (-5,-1)
d. (2,-1)

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.