The answer is A. a cell
hope it helps!
Earth has roughly surface times more atmospheric pressure than mars.
Sorry if it's wrong i tried!
I believe it's stem cells.
The standard operating procedure or SOP is a
written safety and health measures for hazardous tasks. It is a detailed
instructions or step-by-step directions for conducting a specific procedure especially when dealing with
chemicals that may cause injury. Moreover, because of these SOP’s accident and
untoward circumstances in the workplace can be avoided.