Question: Chantal is going to her friend Gregory's house for a dinner party. Gregory had asked Chantal to bring a bottle of wine to drink with the meal. When Chantal goes to the grocery store to pick up a bottle, though, she realizes that she can't remember if Gregory said he was serving beef, chicken, or fish for dinner. She now needs to decide whether to buy a bottle of red or white wine. Her preferences for the various outcomes can be arranged as follows:
While thinking about this decision, she bumps into her friend Shelli, who is also picking up some things for the same dinner party. Shelli doesn't know what is being served either, but she tells Chantal that it couldn't be beef because Gregory's girlfriend doesn't eat red meat. Therefore, Chantal decides to recalibrate the table above with the beef options eliminated (so that "white wine and fish" is the best outcome and "red wine and fish" is the worst outcome). What should Chantal's new preference probability be for the outcome "white wine and chicken?"
a. 0.7
b. 0.8
c. 0.9
d. There is not enough information to decide.