Answer: B.
Explanation: Cytosis in this context is the taking in, and releasing of various nutrients, proteins, toxins, etc. in and out of the cell. This is facilitated by the plasma membrane because it's our wall that surrounds the cell deciding who goes in and who goes out.
Fluid balance is roughly equivalent to the water balance in the human body.
The average height of the oceans surface between high and low tides is called the sea level. It is important to know this measurement because with this it is possible that we can calculate the height of anything on the land. Also, we can <span> calculate the height of anything on the land. Also, we can be able to determine whether the oceans are falling or rising through time.
So the answer is </span><span>Sea level </span>