Select from options: Continue writing the next sentence.

How to clean out a humidifier
Rinse the filter.
Unplug the humidifier first, then remove the filter. Hold it under the faucet and rinse it with cold water to wash away any impurities.

OPTIONS:
[a]. Submerge the filter in your bucket of water to remove bubbles. Rinse the filter with water from your tap to rinse out any impurities or urine that is trapped in the filter.
[b]. Set it on a clean towel to dry while you clean the remaining parts. Don't use cleaning solution to clean the filter.
[c]. You can also rinse with a cleaned filter, if you think your humidifier may smell smelly. A cup of water after rinsing the humidifier is fine; you should simply pour water over the filter to wet it and give it a quick wipe down.
[d]. Seal the filter, then open the door to allow the air to escape. Remove the spinner head and washing knob.
Answer:
[b].