Magma! I think and hope this helps
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
Answer: The answer is the last option, Backflow of blood through a defective valve.
Explanation: Hypotension causes high blood pressure, and the other two options are not related to heart murmurs. A hear murmur is when the blood isn't flowing in the right direction causing the hear to beat irregularaly.
I believe the answer is C. 10 inches per day
