The part of the computer that contains the brain, or central processing unit, is also known as the

Central Processing Unit (CPU.).  Is the  brain or the heart of a computer.  Is also known as Microprocessor and Consist of three (3)  Units:

A):  Control Unit (CU)

B):   Arithmetic Logic Unit ( ALU)

C):   Main Memory Unit ( MMU)

Therefore, Your Answer > Microprocessor, or The System Unit contains the Central Processing Unit (CPU.).

Hope that helps                                                  : )