Read the passage from part 1 of “to build a fire.”

it made quick efforts to lick the ice off its legs, then dropped down in the snow and began to bite out the ice that had formed between the toes. this was a matter of instinct. to permit the ice to remain would mean sore feet. it did not know this. it merely obeyed the mysterious prompting that arose from the deep crypts of its being. but the man knew, having achieved a judgment on the subject, and he removed the mitten from his right hand and tear out the ice particles.

what does the dog’s reaction reveal about it?

it responds to natural impulses.
it ignores painful symptoms.
it appreciates the man’s .
it understands the risks of frostbite