​People tend to eat more at all you can eat buffets than they would at any other restaurants.This is so because the cost of consuming an additional item at an all you can eat buffet is

A) ​negative
B) zero
C) positive
D) ​None of the above

All You Can Eat

A service model where diners pay a set fee to consume as much food as they desire from a specific selection.

Consumption

The use of goods and services by households.

Additional Item

A supplementary product or service added to an existing order or purchase.