Dave and Buster Play Two Games of Tennis,then Decide to Go

Multiple Choice

Dave and Buster play two games of tennis,then decide to go have lunch.Using the concept of utility to explain their choices,we can conclude that:

A) they each won one game of tennis.
B) the marginal utility from playing a third game must be negative for them.
C) the marginal utility from playing a third game must be less than the utility from having lunch.
D) All of these must be true.