What protocol enables Transmission Control Protocol/Internet Protocol (TCP/IP) to internetwork?

The protocol that enables Transmission Control Protocol/Internet Protocol (TCP/IP) to internetwork is Internet Protocol (IP). IP is a fundamental protocol within the TCP/IP suite, serving as the primary means by which data is routed and delivered across diverse networks. It provides the necessary addressing and routing capabilities that facilitate communication between different networks, allowing devices on different IP networks to communicate effectively.

IP operates on a packet-based system, encapsulating data from the transport layer (where TCP operates) and adding headers that include source and destination IP addresses. This addressing ensures that packets can traverse multiple networks and reach their intended destinations, effectively enabling internetworking.

In contrast, Trivial File Transfer Protocol (TFTP), Dynamic Host Configuration Protocol (DHCP), and Simple Network Management Protocol (SNMP) serve different functions within the networking context but do not provide the core routing and addressing functionalities necessary for internetworking like IP does. TFTP is primarily used for simple file transfers, DHCP is used for assigning IP addresses to devices on a network, and SNMP is utilized for network management and monitoring. Therefore, Internet Protocol is the correct answer.