This type of filter is meant to remove smaller particles.

• A. Carbon filters
• B. HEPA filter
• C. Bag filter
• D. Media filter

Answer: (D)

Filtration efficiency depends on how fine a filter’s media is and how much surface area it presents. Media filters use pleated, high-surface-area media with finer pore structure, which lets them catch smaller particles than standard bag filters while staying less costly and energy-intensive than a full HEPA system. Carbon filters target gases and odors, not particle size; HEPA is designed to trap very small particles at very high efficiency, but in many building systems the mid-range option to remove smaller particles is the media filter. Bag filters mainly catch larger particles, so they don’t address the finer dust as effectively. That’s why this type of filter is described as removing smaller particles.