Which of the following loads is generally considered a continuous load?

A continuous load is defined as a load where the maximum current is expected to continue for three hours or more. In the context of this question, an electric sign installed at the front of a retail store is considered a continuous load because it typically operates for extended periods, especially in retail environments where it may be on for an entire day to attract customers.

The refrigerator operates continuously but does not necessarily draw its maximum current for three hours straight due to its cycling nature. Similarly, an electric clothes dryer and an electric range are used in a way that does not generally maintain peak loads continuously for that duration. They typically have intermittent use, especially since clothes dryers and electric ranges are used in shorter bursts of activity. Therefore, the sign stands out as the only choice among the options that fulfills the criteria of a continuous load by being consistently operational over long periods, particularly during store hours.