Autility company charges $0.28 per kilowatt hour of electricity plus a $35 basic connection fee each month. which function models an electric bill as a function of electricity usage (k)? a) f(k) = 0.28k + 35 b) f(k) = 0.35k + 28 c) f(k) = 0.28k − 35 d) f(k) = −0.28k + 35