Why is C incorrect?

Hello @amf, Here is my diagram for the stimulus. Decaf & Carl's - -> FR or MJ We are then told that Yusuf only serves decaf, so this gives us one of the sufficient conditions. We are also told that the coffee was not French Roast, leaving us with this: Carl's - -> MJ To summarize: Two possibilities are presented. One of those options is eliminated. If the sufficient condition is fulfilled, then the other option will follow. So, what is wrong with C? It has a conditional conclusion, but not the kind we are looking for because both options are eliminated. Rose doesn't settle on either July or October. We want the following format: P: A - - > B or C P: not C C: A - -> B