Explanation:

On a computer motherboard, information travels between various components, such as the CPU, RAM, and peripheral controllers, through a system of electrical pathways known as a "Bus." A bus is a communication system that facilitates the transfer of data, addresses, and control signals between different parts of a computer. Option (a) "Flash memory" is a type of non-volatile computer memory used for storage. Option (b) "CMOS" (Complementary Metal-Oxide-Semiconductor) refers to a small amount of memory on the motherboard that stores BIOS settings, not a data transfer pathway. Option (c) "Port" is an interface used to connect external peripheral devices to the computer, not for internal component communication. Therefore, (d) Bus is the correct answer as it is the fundamental mechanism for internal data transfer.