Final answer:
When tying in conductors, use a 16-gauge wire for #4 and smaller, a 14-gauge wire for 1/0 to #4, and a 12-gauge wire for larger than 1/0 to adhere to electrical safety and reliability standards.
Step-by-step explanation:
When selecting tie wire size to tie in conductors, it is important to use the appropriate size to ensure both electrical safety and reliability. Based on the American Wire Gauge (AWG) system, for conductors that are #4 and smaller, a 16-gauge tie wire would typically be suitable, which corresponds to option c. For conductors from 1/0 to #4, a 14-gauge tie wire, representing option b, is generally used. Lastly, for conductors larger than 1/0, a 12-gauge tie wire is commonly chosen, aligning with option a. It is essential to follow both local and national electrical codes and standards when choosing tie wire sizes. The selection should consider the current-carrying capacity, the physical strength of the wire needed to secure the conductors, and the environment in which the wiring system will operate.