which of the following is a nash equilibrium? select one or more: a. it is not possible to define a nash equilibrium in this game. b. both going to the pizza place (pizza, pizza) c. aaron going to pizza place and betsy going to the soup place (pizza, soup) d. there is no nash equilibrium. e. aaron going to soup place and betsy going to pizza place (soup, pizza) f. both going to the soup place (soup, soup)