Make a key decision Trophy in Hitchhiker: A Mystery Game
Make a key decision
Waitresses have to be whatever people want them to be.
How to unlock Make a key decisionStory-Related and Cannot be Missed
This sounds like it may matter on which you choose, but you will receive the trophy either way and the resulting conversation will be the same. When you are in the Diner with Leah during Ride 3, she will begin pretending to talk to you on the phone and start roleplaying as Keira, your girlfriend. During this moment, Keira/Leah will say "Let me be her."
Pick either "Yes, you can replace her" or "No, this isn't right." Either way, you will have made the key decision and Keira/Leah will allow you to ask a few questions alluding to the Man from Balkan Tours.