What three factors must be known when sizing AC wiring?

The correct factors to consider when sizing AC wiring involve understanding the specific electrical requirements and environmental conditions that affect wire performance. The choice identifies insulation rating, the environment where the wiring will be installed, and the number of conductors as the relevant factors.

Insulation rating is critical because it defines how well the wire can handle heat produced by the current flowing through it and ensures safety under various operating conditions. The environment includes factors like moisture, temperature fluctuations, and potential exposure to chemicals, all of which can impact the integrity and performance of the wire. The number of conductors is also significant because multiple wires bundled together can generate additional heat, and each conductor has its own load which must be accounted for to prevent overheating and ensure safe operation.

In contrast, the other options either mix different types of considerations or include factors that are not primary in sizing AC wiring. While current rating, voltage drop, and wire length are important for ensuring the wire can handle the electrical load efficiently, they don't capture the environmental aspects necessary for safety and longevity. Additionally, factors like power output and gauge are important but do not encompass the critical considerations presented in the correct choice. Temperature control, insulation thickness, and amperage can be relevant, but they do not cover the specific aspects