Q: In this task, you are given a conversation between a flight agent and the customer. You are given 4 options and you need to select the goal of the conversation. It is provided as part of customer's context, which has to be one of the following: `book`: Make a new reservation, `cancel`: Cancel an existing reservation, `no_flight`: No flight found for the customer's preference, `no_reservation`: No reservation / No change / No cancellation was made in the conversation, mostly enquiring details
customer: Hello. 
 agent: Hello, how can I aid you today? 
 customer: Can you please help me to find a flight on the route from DCA to OAK for my business trip? 
 agent: Sure, when are you planning to start and return on? 
 customer: My journey dates are from November 13th to November 15th. 
 agent: Do you need any other specifications? 
 customer: I was looking for a flight with economy class. 
 agent: Can I know your good name? 
 customer: My name is Michelle Campbell. 
 agent: Do you prefer a connecting flight? 
 customer: Yes, my maximum connection limit is 1. 
 agent: Thank you for your details, there are no flights found with the given details. 
 customer: Oh! That's fine, thank you for checking. 
 agent: Thank you. 
 customer: You are most welcome.
A:
no_flight