Select the three Celsius and Fahrenheit insulation temperature ratings listed in Table 310.16.

The correct selection is based on the understanding of the insulation temperature ratings found in Table 310.16 of the National Electrical Code (NEC). This table outlines the maximum allowable conductor temperatures for various types of insulation in different wiring applications.

The ratings typically listed are categorized to correspond with the thermal limits of specific insulation types. For example, the various designations such as I, II, III, etc., refer to different insulation materials and their associated temperature ratings in both Celsius and Fahrenheit.

In this scenario, choosing the first, fourth, and sixth insulation ratings is correct because they correspond with widely used insulation types that are often encountered in practical electrical installation scenarios. The first may refer to a standard type of insulation rated for higher temperature applications, while the fourth and sixth would typically represent common insulation types that can handle medium to high thermal conditions, ensuring safe operation and compliance with safety regulations.

Understanding this table is crucial for making informed decisions about wire selection based on the application’s thermal characteristics, environmental conditions, and safety standards.