(a) What is the meaning of the derivative S '(T)? S '(T) is the rate at which oxygen solubility changes with respect to the oxygen solubility. S '(T) is the rate at which temperature changes with respect to the oxygen solubility. S '(T) is the rate at which temperature changes with respect to the temperature. S '(T) is the current level of oxygen solubility for a given temperature. S '(T) is the rate at which oxygen solubility changes with respect to the water temperature.