Answer: Bilbo's indecision about whether he should go on the adventure; his determination to give it a go
Step-by-step explanation:
Conflict resolutions supposes reaching an agreement after pondering all possibilities and versions of the situation. Conflict resolution also means finding a solution to the difficult situation. The correct answer is the one related to Bilbo's indecision, because he was having a strong internal conflict about whether to go on the adventure or not, but he finally took a decision and came up with a solution, after all: to give it a go.
All the other instances do not comprise a solution: the dwarves have a grudge with the goblins, but the dwarves seeking revenge is not a solution. The dwarves telling the burglar they don't welcome him on the voyage isn't a solution either and they haven't reached any conclusion. Gandalf disappearing and then having an illness does not hint at any conflict (internal or between two parties) and his illness definitely isn't a resolution.