Which emergency flotation devices are commonly found on aircraft?

The correct choice highlights that life rafts and emergency slides are essential emergency flotation devices commonly found on aircraft. Life rafts are designed to provide buoyancy and safety for passengers in the event of a water landing. They are equipped with various survival supplies and are deployed from the aircraft when necessary, ensuring that occupants have a means of surviving until rescue.

Emergency slides, while primarily serving the purpose of evacuating passengers during an emergency on land, can also play a critical role in water evacuation scenarios. When an aircraft is immersed in water, the slides can assist passengers in safely departing the aircraft and reaching the life rafts or floating away from the aircraft.

The other choices involve safety equipment that serves different purposes, such as first aid kits and oxygen masks, which are important for medical emergencies and cabin pressure issues but do not relate directly to flotation. Fire extinguishers and toolkits are crucial for in-flight safety and troubleshooting but are also not flotation devices. Flashlights and signaling devices are helpful for emergencies, especially during evacuations or night operations, but they do not serve the specific function of flotation in water scenarios. Thus, the combination of life rafts and emergency slides reflects the focus on flotation safety in the context of aviation.