The answer to your question is B.
Answer:
Water evaporates and ends up in clouds high up in the atmosphere. Since it is colder in the upper atmosphere, the clouds condense.
The right answer is HEPA filter.
A HEPA filter (High Efficiency on Particles Air) can filter up to 99.97% of 0.3μ aerial particles.
These filters are used to clean the air and retain suspended particles (dust, pollen, bacteria etc.) and other particles that can cause respiratory allergy in sensitive subjects.
They are very used in sterile rooms
Can you give all of the characteristics of the atom carbon?