Frequent Fliers If You Think George Clooney's Character in the Movie Up

Frequent Fliers
If you think George Clooney's character in the movie Up in the Air was pure fiction,think again.Clooney portrayed a frequent flier who enjoyed top-of-the-line perks the likes of which even most "elite" fliers don't experience.That's because he was a member of American Airline's invitation-only ConciergeKey recognition program.Most airlines maintain these unpublished super elite frequent-flier plans,such as Continental's Chairman's Circle and Delta's Executive Partner programs.These programs are reserved for the highest-volume customers in terms of miles flown or highest-value in terms of revenue.You'll have to fly upwards of 300,000 miles or spend $50,000 a year to be invited.
-Refer to Frequent Fliers.Airlines' commitment to providing premium customer service to its most valuable customers indicates a commitment to:

A) customer relations mapping (CRM)
B) consumer relationship marketing (CRM)
C) internal transactional marketing
D) customer relationship management (CRM)
E) consumer replacement market (CRM)