Conductors connected in parallel in general wiring systems shall be at least No. _______ or larger.

In electrical wiring, particularly for conductors connected in parallel, the requirement that they be at least No. 1/0 or larger is based on standards set by regulatory bodies, such as the National Electrical Code (NEC) in the United States. This guideline ensures that the conductors can safely carry the combined load without overheating or causing a fire hazard.

Using conductors that are No. 1/0 or larger ensures sufficient ampacity, which is the maximum amount of electrical current a conductor can carry before exceeding its temperature rating. This is crucial in parallel wiring because the ampacity of each conductor is additive; if smaller conductors were used, they might not be able to handle the total current flowing through the parallel arrangement. Hence, specifying a minimum size of No. 1/0 helps maintain safety and reliability in the electrical system.

The other choices do not meet the necessary ampacity requirements for conductors connected in parallel, making No. 1/0 the appropriate minimum size for such configurations.