Final answer:
Class 2 circuits can be installed with Class 1 circuits if they are functionally associated. This addresses safe installation practices in electrical engineering, taking into account the challenges high-voltage circuits pose to circuit interruption and the use of insulating gases in large breakers. Therefore option (C) is correct.
Step-by-step explanation:
Class 2 circuits may be installed in the same enclosure or cable with conductors of Class 1 circuits provided they are functionally associated. The standards and regulations that electrical engineers and electricians must adhere to when constructing and maintaining electrical circuits.
The other options refer to voltage insulation requirements which are not the correct answer to this question. When dealing with high-voltage electricity, it's crucial to consider not only the functional association but also the safety measures to prevent sparks or arcs that can occur when a circuit breaker interrupts the flow, especially in the case of high-voltage and large current systems.
Advanced circuit breakers use insulating gas and gas jets to blow out sparks, and AC is often considered safer than DC because it periodically passes through zero voltage, aiding in the extinction of electrical arcs.