Final answer:
The lost umbrella should be addressed at the Lost and Found Office at the airport, considering the context provided regarding the Sky Train and the terminal's connection to the airport.
Step-by-step explanation:
A passenger claiming to have lost an umbrella should be directed to apply to the Lost and Found Office at the location where the item was likely misplaced.
Since the reference information mentions the Sky Train at a terminal, which is associated with transit to a rental-car and long-term parking center and has waiting times for the train that follow a uniform distribution, it is reasonable to assume that the airport is the place being referred to. Therefore, in this context, the passenger should be guided to the Lost and Found Office at the airport.