Answer:
B) to stand stiffly
Step-by-step explanation:
The best meaning for the word "bristle" as used in the passage is TO STAND STIFFLY because from the narration given, not long after the dog had seen him, he stood stiffly and began to growl.
The word "bristle" as a noun means a short hair on the skin of an animal, however the meaning of the word as a noun is to "stand stiffly" which was what the dog did because it was an action, not a noun.