The correct answer is Control unit, arithmetic logic unit, registers.Central Processing Unit (CPU): It is the most important unit, where all the processing jobs take place.CPU is the control centre of the computer and hence it is said to be the brain of the computer. CPU has three main components:Arithmetic Logic Unit (ALU):It performs all the arithmetic operations like addition (+), multiplication (*), subtraction (-), division (/) on the numerical data directed by the control unit. All the logical operations, like less than (<), greater than (>), equal to (=), not equal to (?), etc. are also carried out by ALU.Control Unit (CU): ?It controls and coordinates all the operations taking place in the system.It controls the flow of data and information from one unit to the other.Registers/Memory Unit (MU):To execute a program, data and instructions need to be stored temporarily.This storage is done in the MU. The data and instructions are retrieved from MU by Control Unit for supplying to ALU as when required by the program.