Final answer:
Boats up to 9m must have a combo of safety equipment that includes lifejackets, a bailer, and a sound signaling device to ensure safety and the ability to signal for help in case of emergency.
Step-by-step explanation:
The safety equipment required for boats up to 9m includes more than just lifejackets. According to safety regulations, these boats must also have additional safety gear. For instance, they need to have a bailer to remove water that may accumulate in the boat, ensuring it does not capsize or become unmanageable. Moreover, a sound-producing device is necessary for signaling help in case of an emergency at sea or on the water.
Therefore, the correct answer to what safety equipment boats up to 9m must have is: d. Lifejackets, a bailer, and a sound-signaling device. This combination of equipment helps ensure that individuals on the boat can keep themselves safe and seek help if they are in distress.