ZipCar locates its cars on many college campuses. Due to the high concentration of Millennials on campuses, it is likely that ZipCar can serve more of its members with a smaller number of cars per member on these campuses than in areas that have a lower concentration of ZipCar members. This greater efficiency probably makes the Millennial segment more?

a. profitable.
b. substantial.
c. responsive and identifiable.
d. identifiable.
e. responsive.