Which of the following connections is typically used for fire hoses?

Fire hoses are primarily designed to withstand high pressures while being both flexible and durable. The correct choice, rubber, is widely used for fire hoses due to its excellent elasticity, strength, and resistance to abrasion and weathering, which are essential properties when dealing with the various conditions fire fighters encounter. Rubber hoses can easily expand under pressure and return to their original shape, which allows for effective water delivery during firefighting operations.

While other materials like stainless steel can be used in components such as fittings or couplings due to their durability and resistance to corrosion, they do not possess the flexibility that rubber provides. Copper and plastic may not offer the necessary resilience and could fail under the demands of high-pressure firefighting scenarios. Therefore, rubber stands out as the most suitable choice for fire hoses, combining strength with flexibility for efficient use in emergency situations.