Which of the following is an incorrect description pertaining to the common components that make up computer systems?
A. General registers are commonly used to hold temporary processing data, while special registers are used to hold process characteristic data as in condition bits.
B. A processer sends a memory address and a "read" request down an address bus and a memory address and write request down an I/O bus.
C. Process-to-process communication commonly takes place through memory stacks, which are made up of individually addressed buffer locations.
D. A CPU uses a stack return pointer to keep track of the next instruction sets it needs to process.