Which layer manages the reliable transfer of data from host to host (or end to end) in OSI model?

The network layer will deliver data from one end to another but it will do so individually.

This means that it will not have any relation to the other data that are being sent with it. The transport layer, on the other hand, will take the whole message, as one big data and will then transport the message from end to end. The answer will depend on the type of data that you are sending.

Network layer is responsible for host to host communication whereas transport layer takes care of communication between 2 processes.