The processing capability of a microcomputer can be enhanced with the help of

Option A: addition processor:
This isn't a standard term. While adding more cores to a CPU helps, it's usually done through a motherboard upgrade, not an "addition processor."

Option B: expansion cards:
This is the correct answer.
Expansion cards are like add-ons you plug into your computer's motherboard.
They can add new functionalities or improve existing ones.
For example, you can add a graphics card (GPU) to enhance video processing,
a sound card to improve audio, or a network card for faster internet.
These improvements directly enhance the microcomputer's processing capabilities.

Option C: secondary memory:
Secondary memory (like a hard drive or SSD) is for storing data.
It doesn't directly make the computer process information faster.
It only allows you to store more data.

Option D: buffer memory:
Buffer memory is a small, fast memory used to temporarily store data during processing.
While it helps with data flow, it doesn't significantly enhance the overall processing capability of the microcomputer.
It's more of a fine-tuning mechanism.

Option E: None of the above:
Since option B is correct, this option is incorrect.

Therefore, the best answer is B: expansion cards because they provide a direct way to enhance a microcomputer's processing capabilities by adding dedicated hardware for specific tasks.