DHT 2 is utilized in which type of service?

The correct choice is Gas Oil, as DHT 2, or Diesel Hydrotreating Unit, is specifically designed to process gas oils. In an oil refinery, gas oils are heavier fractions that fall between kerosene and residual oils. The hydrotreating process is crucial as it removes impurities such as sulfur and nitrogen, thereby improving the quality of products derived from this fraction, including diesel fuel.

In the context of the other options, while jet fuel and light hydrocarbons may require hydrotreating, they typically utilize different configurations or processes. Heavy fuel oils also have their own treatment specifications and usually do not pass through units designed primarily for gas oil processing. Therefore, the specialization of DHT 2 in processing gas oil aligns with its primary function in the refinery operations.