Why does bilbo give the arkenstone to bard and the elvenking? a. he believes it will prevent a war. b. he feels guilty for having stolen it. c. he is angry with thorin and wishes to end their friendship. d. he wishes to be thought of as an honest hobbit

Bilbo gives the Arkenstone of Thrain, 'the Heart of the Mountain', to Bard to aid him in his bargaining with Thorin. Bilbo recognizes the importance of the jewel, telling Bard that "it is also the heart of Thorin. He values it above a river of gold
Bilbo gives the arkenstone to bard because he believes it will assist him when bargaining with Thorin.