In air sample analysis, Phase Contrast Microscopy is abbreviated as which option?

• A. PCM (Liquid)
• B. Polarized Light Microscopy
• C. Phase Contrast Microscopy
• D. PCM (Air)

Answer: (D)

The main idea is that Phase Contrast Microscopy is abbreviated PCM, and in air sample analysis the convention is to include the sample type in parentheses to show the medium being studied. PCM (Air) indicates you’re applying Phase Contrast Microscopy to an air sample, which is the typical context for counting airborne particles without staining. This technique lets transparent airborne particles be seen clearly, making it the appropriate method for air monitoring. The other options point to different ideas: Polarized Light Microscopy is a different method, PCM (Liquid) would apply to liquids, and writing out the full name isn’t the abbreviation. So PCM (Air) is the appropriate label.