Question

Why does bilbo bring home only two small chest filled with treasure from the mountain

a. he has no need for more
b. he loses most of his treasure on the way home over the misty mountains
c. Thorin forbids him to take more
d. He donates most of his share to the people of lake town

Answer 1

Upon his return from the battle, Bilbo comes back with two little treasure chests, one filled with silver and the other one with gold, and says "That will be quite as much as I can manage". Taking this into consideration, we can conclude that your best answer is option A.