Insulated Electrical Wires Often Have a Maximum Voltage Rating,i

Multiple Choice

Insulated electrical wires often have a maximum voltage rating,i.e.,the insulation on the wire is safe up to the rated voltage.The reason why the insulator is not safe at higher voltage is because

A) there is a possibility of electric breakdown,which will cause electrons in the valence band of the insulator to be promoted to the conduction band making the insulator a conductor.
B) the wire will then carry more current,making the wire unsafe.
C) most households only have 240 V maximum so there is no point having a higher voltage rating.
D) it is the manufacturer's way of preventing users from transmitting higher voltage.
E) None of these is correct.