Final answer:
A computer needs a CPU and RAM to perform the four essential functions of computing: input, process, output, and storage. These components work together to process and temporarily store data, making option A the correct answer.
Step-by-step explanation:
To perform the four essential functions of computing, which are input, process, output, and storage, a computer requires specific components. The correct components for these functions are the Central Processing Unit (CPU) and Random Access Memory (RAM), which corresponds to option A) CPU and RAM. The CPU is the brain of the computer, responsible for processing all instructions from both hardware and software. RAM is a type of computer memory that can be accessed randomly; it is the main memory in a computer and works with the CPU to process data.
While other components such as the monitor, keyboard, hard drive, and graphics card also play important roles in a computer's operation, they do not directly facilitate the core computational functions like the CPU and RAM do. Similarly, the operating system and software are necessary for a computer to perform specific tasks, but they are not hardware components; rather, they provide instructions and interfaces for the hardware to execute tasks.