Who employs the RDP in responsible charge for structural observations?

The correct answer identifies that the owner or owner's agent employs the Registered Design Professional (RDP) in responsible charge for structural observations. This is fundamental because the role of the RDP is to ensure that the structural elements of a project are designed and constructed in accordance with relevant codes and standards. The owner or their designated representative has the authority to hire the RDP, who then takes responsibility for overseeing these aspects during construction.

By employing the RDP directly, the owner ensures that they have an expert in structural integrity monitoring on-site, which is crucial for maintaining safety and compliance throughout the construction process. The RDP acts as an intermediary who interprets plans, provides guidance, and ensures that any deviations from the approved design are addressed adequately.

This direct employment relationship also aligns the RDP's responsibilities with the interests of the owner, fostering a proactive approach to identifying issues and ensuring that the construction meets the specified standards. Other options do not establish this level of responsibility or authority over the architectural and structural oversight needed during construction.