the definition for ‘shun’ is “persistently avoid, ignore, or reject (someone or something) through antipathy or caution.” so the correct answer would be
C. “Ever since that dog chased after me, I shun walking by his house.”
This is because since you were chased by the dog, you would want to avoid going near it and that would mean staying away from the house, therefore, persistently avoiding the house out of caution just like the definition says
hope this helps :)