This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to clean a cpap
Disassemble your headgear.
Separate your mask from the headgear by detaching the arms that secure it to the outer frame and fabric backstrap. Then gently pull the mask away from the ring that connects it to the tube.

pick from the following. (a). You'll only need one arm, so use one arm to disassemble your head. If the mask is too bulky to clean and its outer surface needs to be taken off, pull it just off.; (b). Clean the headgear using a hose and clean to 75% capacity. Place your head over the bucket of cleaning solution, mist or soak an old toothbrush to remove dirt, grease, trapped water, dust, and lingering bacteria.; (c). Inspect the headgear for bacteria or other microorganisms while removing it. Remember to clean the tube thoroughly before replacing it.; (d). Check your machine's user guide for more specific instructions on disassembly. Hand wash the mask with soapy water.;
The answer is:
(d).