For the expression 6 + y − 3, determine the coefficient for the variable term.
a: -3
b: 0
c: 1
d: 6

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.