Economists Believe That People Who Force Themselves to Always Eat

Economists believe that people who force themselves to always eat everything on their plate at a restaurant,regardless of how full they might feel,likely do so because:

A) they gain negative utility from insulting the chef.
B) they overvalue the opportunity costs of their health and time involved with eating food they don't really want.
C) they include the sunk cost of their meals in making their decision.
D) they undervalue the true benefit of eating too much.