To determine which detail best supports the answer to Part A, we would need to know what Part A is asking. However, based on the given options, it seems that details about Lewis's experiences with bears and his mindset regarding the dangers they posed are the focus.
If Part A is about the dangers Lewis and the Corps faced from bears, the best supporting detail would likely be:
“Even at camp, he insisted they should sleep with their guns beside them in case of sudden bear attacks.”
This detail highlights the seriousness of the threat bears posed to Lewis and his group, indicating that they were constantly aware of the danger. If you provide the specific question from Part A, I could give a more precise answer.