A technician routing a fuel hose within an engine room should use which type of hose?

The correct choice is A1, which refers to a type of fuel hose specifically designed for high-pressure fuel applications in marine environments. This designation indicates that the hose can withstand the harsh conditions often found in engine rooms, such as exposure to fuel, oil, and high temperatures.

Using A1-rated hoses is critical because they are constructed with materials that resist permeation, which helps prevent fuel leaks and minimizes the risk of fire hazards. Additionally, A1 hoses typically have a higher fire resistance rating, ensuring they can handle potential ignition sources present in the engine room without failing.

In contrast, hoses rated B1 or B2 are typically used for less critical applications or for lower pressure scenarios, making them unsuitable for high-pressure fuel systems. A2 hoses might be appropriate for certain applications as well, but they do not meet the specific requirements for high pressure or performance under potential fire conditions in an engine room context. Selecting the appropriate hose type is essential for safety and compliance with industry standards.