This is a rubber fuel hose elbow at the diesel injection pump using 2 x 13mm hose clamps, one at each end.
This hose replaces hose 647 078 03 81, which has been discontinued. This is the UPPER elbow hose at the injection pump.
This hose has one end which has a larger inside diameter on one end of the hose.
Fuel Hose B is similar in appearance however, both ends have the same size inside diameter and is located right below this hose