The IEC developed a standard to rate DMMs based on what characteristic?

The correct choice highlights that the IEC (International Electrotechnical Commission) developed a standard to rate Digital Multimeters (DMMs) primarily based on their ability to handle maximum voltage spikes. This characteristic is crucial as it defines the maximum voltage that a DMM can withstand without being damaged or providing inaccurate readings. By rating DMMs based on their tolerance to high voltage spikes, the IEC ensures that users can select meters that are robust enough for their applications, particularly in environments where voltage surges can occur.

When considering DMMs, it's important for users to understand not only the operational limits of the meters but also their safety features. This rating helps in effectively preventing electrical shocks and ensuring reliability during testing and measurement.

Other options such as wattage capacity, total resistance, and frequency response, while relevant to a DMM's functionality, do not serve as the primary characteristic for standardization by the IEC. Wattage capacity may refer to power consumption rather than measurement limits, total resistance is a measurement feature rather than a safety concern, and frequency response relates to the ability of the DMM to accurately measure AC signals at different frequencies but does not address how well it can handle potentially damaging voltage levels.