Advance-purchase discounts offered by airlines are an example of​

A) ​Direct price discrimination
B) Indirect price discrimination
C) All of the above
D) ​None of the above

This is an example of indirect price discrimination, as it is a discount offered based on the timing of the purchase rather than any individual characteristics of the consumer. This allows airlines to charge higher prices to consumers who need to purchase tickets closer to the date of travel, while still filling seats and maximizing revenue.