What is required as written consent from the authority having jurisdiction?

The correct answer is "special permission" because in the context of the National Electrical Code (NEC), written consent from the authority having jurisdiction (AHJ) often refers to any explicit approval or authorization that is necessary for a specific situation, such as a unique installation, a deviation from standard practices, or other scenarios that fall outside typical codes and regulations. This special permission indicates that the AHJ has evaluated the circumstances and has granted approval, ensuring compliance with safety standards and regulations.

Other options, while related to the process of obtaining permissions and approvals, do not specifically connote the direct endorsement or unique allowance that special permission implies. A contractual agreement is more about legal relationships and obligations between parties, site approval is often part of a broader evaluation of plans rather than an individual allowance, and a permit application is typically the initial step in the process, which may or may not lead to special permission depending on the situation at hand. Special permission stands out as it demonstrates authoritative consent for particular actions within the scope of the NEC.