Hypoxemia hypoxia

A patient with hypoxemia due to high altitude would be expected to exhibit which of the following characteristics?

1: A widened A-a gradient and poor response to supplemental O 2
2: A normal A-a gradient and good response to supplemental O 2
3: A widened A-a gradient and good response to supplemental O 2
4: A normal A-a gradient and a poor response to supplemental O 2