Indications for Pulse Oximetry Include Which of the Following

Indications for pulse oximetry include which of the following?
1) To assess changes in HbO₂ during certain procedures
2) To measure abnormal Hb
3) To comply with external regulations or recommendations
4) To monitor the adequacy of HbO₂ saturation

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