What do all computers using the TCP/IP suite have in common?

The correct answer indicates that each computer using the TCP/IP suite is assigned its own Internet Protocol (IP) address. The IP address is fundamental to the way devices communicate over a network, as it serves as a unique identifier for each device within a given network. This unique address allows for the routing of data packets, ensuring that information sent over the internet reaches the correct destination.

With IP addresses, devices can be categorized into different networks, and communications can be managed more effectively. Each IP address must be unique within the same network to avoid conflicts and ensure proper data transmission. This characteristic is essential for maintaining the structure and functionality of internet communications.

In contrast, while redundancy in Internet connections can enhance reliability, it is not a requirement for all TCP/IP computers. Similarly, a common physical address (such as a MAC address) is not shared among devices, as each network interface controller (NIC) has a unique MAC address. The options pertaining to shared addresses do not apply to all devices using TCP/IP, since each device operates independently with its own set of addresses.