Cell Membrane is the answer
Answer:
Replacing a lipid containing 18 C fatty acids with one containing 16 C fatty acids.
During an emergency what you would usually want to do is a so-called threat and hazard analysis - C.
You would do this because you would want to observe and note which is a source of threat for you in a certain emergency situation. You would also to this to observe the possible hazards of doing a certain action/certain actions.