David is helping support a charity bike race. he is in charge of putting in a water station for the bikers halfway between the start and finish lines. the function f(x) = x/4 - 8 models davids distance in miles from the water stand x minutes into the bike race. after 12 minutes, how far away from the water station would the bikers be a) -5 miles
b) 5 miles
c) 11 miles
d) 16 miles