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: Hi. 
 agent: Hello, how can I help you? 
 customer: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that? 
 agent: Sure, may I know your name? 
 customer: I am Carol Clark. 
 agent: Please wait a second. 
 customer: Sure. 
 agent: Sorry, no reservation found on your name. 
 customer: Ok, no problem. Thanks for the information. 
 agent: Thank you for opting us.
A:
no_reservation