Answer: The correct answer is "D. the benefit of lower prices to be greater than the cost of reduced services and less convenience.".
Explanation: Consumers obviously consider the benefit of lower prices to be greater than the cost of reduced services and less convenience.
Discount and no-frills airlines have less costs to cover so they can offer lower and more affordable prices for consumers. These airlines have been successful because it turns out that consumers value or prefer the lower price rather than the additional services.