A man is walking a triangular path, partially represented by the vectors AB−⇀−=⟨0,10⟩ and CA−⇀−=⟨−12,0⟩ . If his distance is represented in miles, which of these best represents the distance the man travels southwest from point B to point C? A 10 miles B 12 miles C 14.9 miles D 15.6 miles