it has to be 2%
answer: decreasing pressure
explanation: solubility of a gas is governed by henry's law.
according to henry's law, the solubility of a gas in a liquid is directly proportional to the pressure of the gas in equilibrium with the liquid at that temperature.
where, = mole fraction of gas in the solution
= partial pressure of the gas above solution
the solubility of gas increases with decrease in temperature.
thus the solubility of gaseous solute will decrease when the pressure is decreased.
abiotic factors are sunlight, temperature, moisture, wind or water currents, soil type, and nutrient availability.