Step 1: Understanding the Concept:
Microfiltration operates at specific pressures.
The pressure range is characteristic of the process.
Step 2: Key Formula or Approach:
No specific formula.
Need to know the operating pressure for microfiltration.
Step 3: Detailed Explanation:
The usual range of applied pressure in microfiltration is 0-3 bar.
This is lower than ultrafiltration (3-5 bar) and nanofiltration.
Higher pressures are not required.
Thus, the correct range is 0-3 bar.
Step 4: Final Answer:
The usual pressure range in microfiltration is 0-3 bar.
Hence, the correct option is (A).