What is the main characteristic of a Class C ANSI hard hat?

A Class C ANSI hard hat is specifically designed without electrical protection. These hard hats are typically lighter and provide comfort and impact protection suitable for environments where electrical hazards are not a concern. They provide a level of protection against falling objects and impact but do not insulate against electrical shocks or arcs.

In contrast, options involving voltage testing or electrical resistance, such as being tested to 20,000 V or 2200 V, are characteristics that belong to Class E or Class G hard hats, which are designed for electrical work and provide insulation. The option mentioning a short brim only in the front does not accurately describe any specific ANSI class due to the design variations among hard hats. This makes it clear that the defining feature of a Class C hard hat is its lack of electrical protection, making option B the correct answer.