Both crude oil washing and water washing use direct impingement to remove residue from tanks. Crude oil washing has an additional advantage, in utilizing __________.

Correct Answer: Option C — the solvent effect of the crude oil

While both water and crude oil washing rely on mechanical impingement, COW provides a superior cleaning effect due to the solvent properties of the crude oil. This chemical action effectively dissolves oil-based residues and sludge that water alone cannot remove, significantly improving tank cleanliness and reducing cargo retention.