The undissociated form of a weak organic acid HA can be extracted from the aqueous phase into an organic phase using a water-immiscible organic solvent according to the following scheme.

Which of the following is/are correct for this extraction?
I. $$\frac{[HA]_{org}}{[HA]_{aq}}$$ depends on the pH of the aqueous phase
II. HA can be efficiently extracted from basic aqueous solutions
III. $$\frac{[HA]_{org}}{[HA]_{aq}}$$ depends on the initial concentration of HA
IV. $$\frac{[HA]_{org}}{[HA]_{aq} + [A^-]}$$ depends on the pH of the aqueous phase