The term "oily mixture", as defined in the Pollution Prevention Regulations (33 CFR) includes __________.

Correct Answer: Option D — all of the above

33 CFR 151.05 defines an "oily mixture" as a mixture with any oil content, explicitly including oily ballast water, bilge slops, and sludge. These substances are strictly regulated because they pose significant environmental risks if discharged into the sea without proper treatment through an approved oily water separator.