The root that does not represent something edible is B. lav.
Lav root word means wash.
Examples:
Lavabo - wash basin connected to the wall
Lavadero - part of a stream where gold are washed from placers
Lavandera - laundress; washerwoman
Lavatory - a place where one can wash
a. carn - latin in origin meaning flesh or meat. Representing something edible would be carnivorous.
c. mel - latin in origin meaning very pure honey.
d. sal - latin in origin meaning salt. Representing something edible would be salad, salami.
