The correct answer is option C
Wolves generally do not like being close to human beings but their acoustics can be used to identify the pressence of wolves as howling is a natural process in wolves. The wolves call to a signal when they occupy a territory. When researchers walk they howls at every point and another researcher waits for the sound of the wolves and records it with the help of a microphone, if there is response then they announce their pressence or defending territory. If any response is elicited then the researchers move close to the sound as possible.