What is the primary feed used in the crude complex?

The primary feed used in the crude complex is crude oil. This is the fundamental input that refineries process to produce various petroleum products. Crude oil is a raw product that contains a mixture of hydrocarbons and other compounds. It undergoes several refining processes, such as distillation, cracking, and reforming, to separate and convert it into valuable products like gasoline, diesel, jet fuel, and other derivatives.

In the context of a refinery, crude oil is essential as it serves as the starting material for the production of fuels and lubricants. Other options, such as natural gas, gasoline, and kerosene, represent either processed products or different types of fuels rather than the primary feedstock that initiates the refining process. Therefore, the correct answer highlights the importance of crude oil as the foundational substance in refinery operations.