The following household appliances do not need to use a rheostat is a LCD TV B adjustable speed fan C energy saving lamp D adjustable temperature electric iron

The following household appliances do not need to use a rheostat is a LCD TV B adjustable speed fan C energy saving lamp D adjustable temperature electric iron

It's B, adjustable speed fan
The speed regulation methods of electric fan include reactor method, tap method and variable speed method, but the rheostat is not used