If the pulse oximetry device is unable to detect a pulse, what actions would you take? Select all that apply.

A) a. Check the positioning of the device on the patient's finger or body part.
B) b. Increase the oxygen level on the pulse oximeter.
C) c. Check for any obstructions or nail polish on the patient's finger.
D) d. Ensure the patient is properly connected to the device.
E) e. Reapply the device on a different body part.