Explanation: Testing a SART (Search and Rescue Transponder) should follow consistent procedures because this allows for tracking its performance over time. Establishing a baseline by testing in a consistent manner and location helps to identify any degradation or potential issues before they become critical, ensuring the unit will function properly when needed in an emergency. Here's why the other options are incorrect: * **B) Testing of the SART should never be done in port to prevent interference to other vessel’s radars.** Most SARTs have a self-test function that is designed to be used safely without causing significant interference to other radars, even in port. Full operational testing might be restricted, but the self-test is generally permissible. * **C) A SART's battery must be replaced within ninety (90) days after the expiration date imprinted on the unit.** This is incorrect and unsafe. Batteries for critical safety equipment like SARTs must be replaced *before* or *by* the expiration date to ensure full operational capability. Delaying replacement after the expiration date significantly compromises safety. * **D) An at-sea GMDSS maintainer is not able to test a SART because it is hermetically sealed.** While SARTs are typically hermetically sealed to be waterproof and robust, this prevents internal user repair, not external testing. GMDSS maintainers can and do test SARTs using their built-in self-test functions or external test equipment to verify functionality.