Dramatic irony occurs when the audience or reader has information the characters themselves do not. In this case, the reader is aware that much of the Donner Party will not survive, even as they fight to do so. This tension is dramatic irony.
Petulant is incorrect because it means that the volunteers were bad - tempered and volunteers usually are generous.
Clear is incorrect because it is stating that the volunteers were understanding when they were gathering over 100 boxes of food.
Both compassionate and resolute would be good answers for this question since resolute means determined and compassionate means a feeling of concern towards others. However, compassionate would be a better choice since the volunteers are putting all this effort in to help the physical needs (food) of the people in the local pantry.
