Answer:
Source port number and destination port numbers for segment travelling from HOST B to HOST A are : Source port number is y , and Destination port number is x.
Explanation:
Because in problem statement it given that the TCP segments traveling from Host A to Host B have source port number x and destination port number y. So it is clear that that Host A has a port named x and Host B has a port named y and when segments travels from Host B to Host A the Host B's port becomes source and Host A's port becomes source.