The correct options are
A Grass→ Grasshopper →Frog→Wolf
B Eichhornia→ Aquatic insects →Fish →Crocodile
The correct food chains are:
Grass→ Grasshopper →Wolf→ Lion
Eichhornia→ Aquatic insects →Fish →Crocodile
Grass and Eichhornia are producers, grasshoppers and aquatic insects are primary consumers, wolf and fish are secondary consumers which feed on primary consumers. Lion and crocodile are tertiary consumers which feed on secondary consumers.