Final answer:
The subject of this question is OSHA, which is responsible for workplace safety standards. The designated person for excavation work needs to have knowledge about soil classification, protective systems, and safety standards.
Step-by-step explanation:
The subject of this question is OSHA, which stands for Occupational Safety and Health Administration. OSHA is responsible for setting and enforcing workplace safety standards to protect workers from various hazards. One specific requirement mentioned in the question is that a designated person with knowledge related to soil classification, protective systems, and safety standards must be appointed by the employer for excavation work.