The International Oil Pollution Prevention Certificate on a MODU is valid for a period of __________.

Correct Answer: Option D — four years from the date of issue

The International Oil Pollution Prevention (IOPP) Certificate is issued under MARPOL Annex I. For MODUs, this certificate is valid for a maximum period of four years, provided the unit undergoes the required annual and intermediate surveys to ensure that its pollution prevention equipment remains in full compliance with international standards.