A.)because they are insulators

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Option A.

Electric wires are dangerous for human beings. The high votagecan damage or even kill a person.  In order to protect us from the wires, sheilding or covering is done for the wires.
THe materials are non conductors or called insulators. they donot transmit electricity through them. so we are safe.