I'd check to see if the lines are marked as SAE J1527 compliant. That J1527 standard was developed in the mid-80's specifically to define alcohol resistance because even way back then fuel distributors were putting alcohol in gasoline. That said, I have also seen older (and newer) lines deteriorate under the use of E10/ethanol fuels.
IIRC the A1 hoses are rated for use in enclosed space locations, whereas the B2 rated hose is for above deck/non-enclosed uses only, like that in an open skiff where the fuel tank is not enclosed under a deck/bulkhead. The difference between the 2 is in materials and quality of construction and of course, the price.