Computer organization — “brains” of a microcomputer: Colloquially, the component referred to as the “brains” of every microcomputer is the ________ (the unit that fetches and executes instructions).

Introduction / Context:
Public-facing explanations often call the central processing unit the “brains” of the computer because it coordinates the entire instruction execution process and orchestrates data movement. Even in microcomputer systems where the CPU is implemented as a single microprocessor chip (MPU), the conceptual role is still that of the CPU.

Given Data / Assumptions:

• “Microcomputer” implies a system whose CPU is a microprocessor.
• We seek the broad, standard term used across computing education.
• The CPU includes the control unit, ALU, and registers from a functional perspective.

Concept / Approach:
The CPU fetches instructions, decodes them, controls the ALU operations, and manages registers and buses. Although “MPU” refers specifically to a microprocessor device that implements the CPU, the widely taught phrase “brains of the computer” maps to CPU, not to ROM, ALU alone, or peripheral controllers.

Step-by-Step Solution:

Verification / Alternative check:
Textbooks define CPU as comprising control logic and ALU, coordinating program execution. The microprocessor (MPU) is a physical implementation of the CPU on one chip in microcomputers.

Why Other Options Are Wrong:

• ROM: Nonvolatile memory; stores programs but does not execute them.
• ALU: Performs arithmetic/logic but lacks overall control.
• MPU: A device form of CPU; the colloquial “brains” label refers to CPU’s role.
• DMA controller: Offloads memory transfers; not the central executor.

Common Pitfalls:
Equating ALU (a sub-block) with the entire CPU; assuming ROM’s program storage makes it the “brain.”

Final Answer:
CPU