This is only one part of the answer, but its important: high-altitude O2 absorbs much energy from the sun (including radioactivity), which forms the ozone layer. this process protects delicate molecules important to life - most notably dna
Answer: <u>Option C, they digest pathogens</u>
Explanation: Monocytes are involved in the process of digesting pathogens and infected cells, termed as phagocytosis.
Monocytes don't produce antibodies, only B cells can produce antibodies. So, option A and D are incorrect. Also they appear colorless when observed under the microscope. They don't appear granular, so option B is also incorrect.
