For a box requiring a calculation of volume, which of the following suggests a scenario that requires a count of pigtails?

In determining the volume of a box, considering the count of pigtails is crucial when the box is required to facilitate electrical connections. The scenario of feeding multiple receptacles involves using pigtails to connect the power supply to each outlet within the same box.

Pigtails are short wires or conductors used to join two or more wires together, allowing for safe and efficient electrical connections. When multiple receptacles are connected in a single box, each receptacle will typically require its own pigtail, thus directly affecting the calculation of the box's volume to ensure it is adequate for the number of wires entering the box and the necessary splices.

The other scenarios (multiple branches on a circuit, adding extra grounding conductors, and incorporating lighting fixtures) may also involve complex wiring setups, but the specific need for pigtails primarily arises when multiple receptacles are involved, as each connection made via a pigtail adds to the overall wiring density in the box that must be accounted for in volume calculations.