For a 3 BUS architecture, is the below code correct for adding three numbers?

PCout, R = B, Marin, READ, Inc PC
WMFC
MDRout, R = B, IRin
R4outa, R5outb, Select A, ADD, R6in, End

A. CPU B. ALU C. Memory Unit D. I/O Interface

A. Single Input Multiple Drive B. Single Input Multiple Data C. Single Instruction Multiple Drive D. Single Instruction Multiple Data

A. L2 Cache B. L3 Cache C. L1 Cache D. Virtual Cache

A. Instruction Register B. Program Counter C. Accumulator D. None of the above