Which feature is common to all Types of Clothes Dryers?

The correct answer is the option stating that all types of clothes dryers can be coin-operated. This feature is commonly found in commercial settings, such as laundromats, where machines are designed to accept coins or tokens in exchange for the use of the dryer. This accessibility to coin operation does not apply to all dryers universally, particularly those used in residential settings, but it is characteristic of a significant category of dryers in commercial use.

In contrast, not all dryers require attendants for operation, as many modern dryers are designed for self-service. Additionally, while some types of dryers use gas for heating, there are electric dryers that do not. Finally, some dryers, particularly ventless models, do not require external venting, as they operate by condensation. This variety among dryer types highlights the fact that coin operation is a common feature that connects many dryers, especially in specific environments like laundromats.