What must be considered regarding pendant boxes and flexible cord connections?

The correct answer highlights the importance of supporting flexible cords at each end to ensure safe and functional connections. When flexible cords are used, they must be adequately secured to prevent undue stress on the electrical connections, which can lead to damage or failure over time. Proper support helps to maintain the integrity of the cord and minimizes the risk of accidental disconnection or wear at the termination points. This practice is often mandated by electrical codes to promote safety and longevity of the installation.

Considering the other options, the requirement for pendant boxes to contain knockouts is specific to certain installations but does not directly pertain to the safety and functionality of flexible cords. The notion that flexible cord can be used without strain relief is misleading because strain relief is crucial in preventing damage to the cord, which is a key consideration in electrical safety. The idea that pendant boxes must not be installed at all is incorrect, as pendant boxes are often used in various applications, provided they adhere to the relevant codes and standards.