Main details are a main thing that happens in the piece of writing and supporting details are what support the main ones.
The correct choice is option A.
Um I don’t know how far you’ve gotten, so yeah.
Salvas character is starting to change, he’s becoming mentally stronger, he’s becoming more brave. He has to be more tougher now that the only 2 people he had during this trip are gone. He became a leader, he led and helped others, while still keeping himself alive.
It is the same as english it is-Thomas