What is an important reason not to place telephone wires in the same conduit as AC power lines?

The primary reason for not placing telephone wires in the same conduit as AC power lines is to avoid noisy telephone circuits. AC power lines can generate electromagnetic interference (EMI) due to the alternating current flowing through them. This interference can adversely affect the quality of the signals transmitted over telephone wires, leading to disturbances, noise, or reduced communication clarity. By keeping telephone wires separate from AC power lines, you ensure better signal integrity and clearer communication.

The other options may touch upon various aspects of electrical wiring, but they do not address the specific concern of signal clarity and quality in telecommunications, which is directly impacted by electromagnetic interference from nearby AC power lines.