which commercial technology commonly uses plasmas?\no a radio\no a race car\no a television\no a microwave…

Brief Explanations:

Plasma - screen televisions use plasmas. In these TVs, small cells filled with plasma (ionized gas) are used to create images. Radios use electromagnetic waves for signal - transmission, race cars are mechanical vehicles, and microwave ovens use microwaves for heating.

Answer:

C. a television