Final answer:
A HEPA (High-Efficiency Particulate Air) filter removes 99.97% of particles and airborne microorganisms that are 0.3 microns or larger, capturing bacteria, endospores, and many viruses, and are used in various settings including hospitals and home appliances.
Step-by-step explanation:
The type of filter that removes 99.97% of particles and airborne microorganisms 0.3 microns or larger is the HEPA (High-Efficiency Particulate Air) filter. HEPA filters are designed with an effective pore size of 0.3 µm, which is sufficient to capture bacterial cells, endospores, and many viruses as the air passes through the filter. These filters play a crucial role in maintaining sterile environments, and are commonly found in places such as hospital ventilation systems and biological safety cabinets in laboratories to prevent the transmission of airborne microbes. They are also widely used outside of healthcare and research settings, such as in vacuum cleaners, HVAC systems, and air purifiers.
Membrane filters are different in that they are used for liquids and typically have an effective pore size of 0.2 µm, generally used for removing bacteria. However, HEPA filtration is the technology applicable for air filtration with the high efficiency described. Therefore, the correct answer to the student's question is a) HEPA filter.