The cell model/theory is a big one
the atomic model/theory
I think the answer must be B, although A is technically somewhat true too. Though the liver can regulate acid secretion, thus helping to balance the pH of blood by increasing or decreasing the acid secretion (can rid the body of excess acid through urine), the question doesn't specify that it balances the pH levels of BLOOD, and equally, multiple factors in the body have a role in balancing bodily pH levels, thus it is not the primary function of the liver. Thus, it must be B. The cells in the liver release an enzyme called renin, which activates angiotensin, which in turn activates the hormone aldostrene, which controls salt retention and elimination of potassium in the kidneys, thus affecting blood pressure and fluid balance.
Hope I helped! x
<u>Answer:</u> The mass of chlorine needed by the plant per day is 
<u>Explanation:</u>
We are given:
Volume o water treated per day = 25,000,000 gallons
Converting this volume from gallons to liters, we use the conversion factor:
1 gallon = 3.785 L
So, 
Amount of chlorine applied for disinfection = 10 mg/L
Applying unitary method:
For 1 L of water, the amount of chlorine applied is 10 mg
So, for
of water, the amount of chlorine applied will be 
Hence, the mass of chlorine needed by the plant per day is 