Which of the Following Are Common Causes of an Increase

Which of the following are common causes of an increase in the drive to breathe, which would increase the sensation of dyspnea?
1) Hypoxemia
2) Acidosis
3) High fever
4) Hypocapnia

A) 1 and 4 only
B) 2 and 4 only
C) 1, 2, and 3 only
D) 2, 3, and 4 only