The correct answer is A) It requires following additional work procedures and close attention by the crew during cargo operations. Crude oil washing is a cargo tank cleaning method that uses the ship's own cargo oil as the cleaning medium, rather than water. While it is an effective cleaning method, it does require additional procedures and close attention from the crew to be done safely and effectively. The other answer choices are incorrect - crude oil washing does not allow a buildup of cargo residue, its cleaning ability is good, and it results in less cargo retained aboard the ship compared to water washing.