Vessels required to be equipped with an approved backfire flame arrester are（）. A. those with diesel

Vessels required to be equipped with an approved backfire flame arrester are（）. A. those with diesel engines B. all those with gasoline engines C. those with large engines only D. None of the above

According to maritime safety standards, the requirement for an approved backfire flame arrester applies to gasoline-powered vessels, not diesel.

Therefore, the correct choice from the options given is:

B. all those with gasoline engines

This is because gasoline engines have a higher risk of backfiring, which can ignite flammable vapors in the engine compartment; the arrester prevents flames from escaping the carburetor.