Which of the following safety measures is required during the ignition process of mortars?

The correct answer emphasizes the importance of using electric ignition or equivalent means during the ignition process of mortars. This practice significantly enhances safety by allowing operators to initiate the firing sequence from a safe distance. Electric ignition systems reduce the risk associated with manual firing by minimizing the need for personnel to be near the mortars at the time of ignition. This means that there's a decreased likelihood of accidents or injuries caused by misfires or unexpected ignition, as the operators can maintain a safe separation.

Further, using electric or equivalent means aligns with best practices in pyrotechnics, where the control and reliability of the ignition system are critical in preventing accidents. Given the inherent dangers of handling fireworks, employing electronic systems provides a controlled method of igniting the devices, contributing to a safer environment for both operators and spectators. This safety measure is part of a broader framework of regulations and protocols established in NFPA 1123 to ensure that fireworks displays are conducted with the utmost caution and safety.

The other measures listed may not provide the same level of safety enhancements during the ignition process.