According to 33 CFR's, the approval period for a shipboard oil pollution emergency plan expires after __________.

Correct Answer: Option D — five years

33 CFR 155.1030 specifies that the approval period for a Shipboard Oil Pollution Emergency Plan (SOPEP) is five years. Vessels must ensure their plan remains current and approved by the Coast Guard or a recognized organization to maintain compliance with international MARPOL requirements and domestic U.S. regulations.