Explanation: SARTs (Search and Rescue Transponders) are essential GMDSS (Global Maritime Distress and Safety System) safety devices with specific performance standards set by the International Maritime Organization (IMO). These regulations mandate that a SART's battery must be capable of operating for at least **four days (96 hours)** in the stand-by mode. This extended stand-by capacity ensures the device can passively await an X-band radar signal from a searching vessel or aircraft for a sufficient period, maximizing the chances of detection during prolonged search and rescue operations. Following this stand-by period, the SART must also be able to transmit continuously for an additional 8 hours once activated. Therefore, options A and D are incorrect because they fall short of the required 96-hour stand-by time, and option C refers to the post-activation transmission duration, not the stand-by period.