In accordance with 46 CFR 61, which of the following pressure vessels listed on the ship's Certificate of Inspection would be exempt from hydrostatic testing?

Correct Answer: Option D — Refrigeration system receiver tank.

Per 46 CFR 61.10-5, refrigeration system pressure vessels are generally exempt from periodic hydrostatic testing requirements applicable to other pressure vessels. These systems are typically subjected to leak tests and operational inspections rather than the rigorous hydrostatic testing required for boilers, air receivers, or feed tanks under the Code of Federal Regulations.