Which device in a computer system does the address bus interact with primarily?

The address bus primarily interacts with the CPU. The address bus is a critical component of the computer architecture that carries the information necessary for the CPU to access specific addresses in memory or input/output devices. When the CPU needs to read or write data, it uses the address bus to specify the location in RAM (or any other peripheral) it wants to access.

In this context, the CPU sends out addresses over the address bus to identify which piece of data it is interested in. The RAM responds to these addresses by providing the corresponding data requested by the CPU. While there are interactions with other devices, such as hard drives or network interfaces, the address bus’s primary role revolves around the communication between the CPU and the system's memory. Thus, the correct answer highlights the essential relationship between the address bus and the CPU in the operation of the computer system.