A cold ___ tank is used to clean grease and oil off parts.

The use of a cold solvent tank is specifically designed for cleaning greasy and oily parts effectively. Solvents are chemical substances that can dissolve other materials, and when used in a cold tank, they help remove contaminants like grease and oils without requiring heat, which could potentially damage sensitive parts or materials.

In automotive maintenance, a cold solvent tank provides a safe and efficient method to clean parts, ensuring that they are free from any residues that could interfere with the performance or longevity of the components. Solvents are typically chosen for their ability to break down oils and grease, making them ideal for this purpose.

Other substances listed, like water, gasoline, and oil, do not serve the same purpose. Water might not effectively break down certain types of grease or oil, gasoline is highly flammable and unsafe for cleaning tasks, and using oil would not clean other oils but rather add to the contamination. Thus, the cold solvent tank stands out as the correct and safest choice for cleaning grease and oil off automotive parts.