Answer:
c. the network layer
Step-by-step explanation:
The Network layer in the TCP/IP model is responsible for end-to-end forwarding of packets. It handles tasks such as addressing, routing, and packet fragmentation and reassembly. This layer ensures that packets are delivered from the source host to the destination host across different networks by making routing decisions based on network addresses. The Transport layer (option d) primarily focuses on the reliable and orderly delivery of data between processes running on different hosts.