The following description about single-site commissioning, which is wrong?

The following description about single-site commissioning, which is wrong?
A . If the input voltage of the device is not within the required range, rectification suggestions should be made and power-on is strictly prohibited
B . It is strictly forbidden to plug and unplug the power plug and PIU board when power is on
C . In the case of power failure, you can touch the veneer without wearing anti-static wrist or anti-static gloves
D . After checking the single station hardware, make sure that all power switches are in the off position

Answer: C