PVC shall not be permitted where subject to ambient temperature in excess of ________ degrees Fahrenheit unless listed otherwise.

The correct answer is 122 degrees Fahrenheit because the National Electrical Code (NEC) specifically outlines the limitations for the use of Polyvinyl Chloride (PVC) conduit in relation to ambient temperatures. PVC is not designed to withstand high temperatures well, which can lead to issues such as deformation, softening, or even failure of the material when exposed to heat above this threshold.

When PVC is subjected to temperatures exceeding 122 degrees Fahrenheit, it's important to ensure that alternative solutions or materials are utilized, especially if the installation environment is likely to reach or exceed that temperature. This requirement helps ensure the safety, reliability, and longevity of electrical installations while adhering to regulatory standards.

In contrast, temperatures listed in the other options (100, 110, and 130 degrees Fahrenheit) do not align with the established guidelines, making them unsuitable for these specific conditions regarding PVC usage.