Which of the following is a requirement for grounded conductors fed from a feeder?

The requirement for grounded conductors fed from a feeder is that they must be insulated from the supply conductors. This insulation is critical because it helps ensure that there is no unintended contact between the grounded conductors and any live supply conductors. This separation is essential for safety, reducing the risk of short circuits, and preventing electrical shock hazards. Insulated grounded conductors help maintain the integrity of the electrical system and protect individuals and equipment from potential electrical faults.

The other options do not correctly reflect the requirements regarding grounded conductors. While grounded conductors can be connected to equipment grounding conductors, this is not a primary requirement for conductors fed from a feeder. The gauge of the grounded conductors does not need to match that of the supply conductors, as different applications may dictate varying sizes. Additionally, while it is permissible for grounded conductors to be grounded at the feeder panel, this is not a specific requirement that applies universally; in some systems, a grounding point may be located elsewhere.