Given the task definition and input, reply with output. You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: The TR3370 will take you to norwich. Do you need a ticket? Sentence2: Well I have many things to do such as architecture visits or museums or theaters. Anything sound intriguing to you? Sentence3: There are 13 to choose from. Might I suggest the Pembroke College. They have free entrance and are located on Trumpington Street. Sentence4: The number is 01223338100. Sentence5: cool, thanks dude Sentence6: The post code is cb21rf. Can I help with anything else today? Sentence7: I need a train to norwich on Sunday. Sentence8: Yes I would like to go to a college. Sentence9: Thank you! That will be all for today! Sentence10: Do you want tickets? Sentence11: yes if it leave after 19:30. thanks Sentence12: No, I don't need to book now. On the other hand, I'm looking for something to do in the centre of city. Sentence13: I am sorry that os not leaving at the correct time but I have train TR9083 leaving at 19:55. Sentence14: Can I have the postcode? Sentence15: You're welcome. Please reach out to us again, if we can be of further assistance. Good-bye. Sentence16: Yes, can I also get the phone number for Pembroke College? Question: Who has spoken the sentence 13? (A) User (B) System
Answer: (B) System