Which markings must be placed on all electric equipment for identification?

The correct response involves the necessity of identifying electric equipment through the inclusion of both the trademark and the manufacturer's name.

Marking equipment with the manufacturer's name is vital as it provides a direct source for support, warranty claims, and safety recalls. The trademark, on the other hand, is an emblem that signifies the branding of the equipment, helping to ensure consumer confidence in the reliability and quality associated with that brand. These identifiers are essential not only for accountability and traceability but also for ensuring that the equipment complies with various regulations and standards within the electrical industry.

While the other options may include elements that could be useful, they do not fulfill the standard requirements set for equipment identification as effectively as the combination of the trademark and manufacturer's name. For example, including cost or model number is not a standardized identification practice required across all electric equipment, and may not always provide the necessary details for safety and compliance verification.