Question

which is not one of the reasons bilbo took the arkenstone? A he was overcome with temptation from its beauty B the treasure had cast its spell of greed upon him a bit C smaug had promised it to him if he led him to the dwarves D the dwarves had not told him he could not have it as his share of the treasure

Answer 1

I`ve read this book like 9 times, so i`ll take a gander and say it`s C. Smaug had promised it to him if he led him to the dwarves.

Answer 2

I read the book, and Bilbo has to have the Arkenstone! When I went to the movie for the second time with my dad, we saw there is one moment where Smaug hits a pit of gold with his claw or tail and then both Arkenstone and Bilbo are out of sight for a short while. That is the only moment when Bilbo could have caught the Arkenstone.