Which of the following voltage configurations describes most residential services?

Most residential services in the United States utilize a 120/240-volt configuration. This system comprises two hot wires that deliver 120 volts each to ground and can provide 240 volts when combined. The 120-volt circuits are primarily used for standard household appliances and outlets, while the 240-volt supply is typically for larger appliances, such as dryers and ovens.

This configuration is specifically designed to meet the varying power requirements of typical household electrical loads. The 120/240-volt system provides a versatile and efficient means of distributing power in a residential setting, making it the standard choice for home electrical systems.

The other options refer to voltages used in commercial or industrial settings, which typically require different voltage configurations due to their higher power demands or specific equipment needs. Thus, these configurations are not common in typical residential wiring.