Which of the Following Measures Is/are Useful Indicators in Assessing $\dot { Q }$

Which of the following measures is/are useful indicators in assessing the adequacy of a patient's oxygenation?
I.PaO₂-PaO₂
II.PaO₂-to-FIO₂ ratio
III.V_D/V_T
IV.pulmonary shunt ( $\dot { Q }$ _s/ $\dot { Q }$ _t)

A) I and II
B) I and III
C) II and III
D) I, II, and III