Concept:Two vectors are perpendicular when their dot product equals zero.Explanation:Let the required vector be (x,y).For perpendicularity, (−1,3)⋅(x,y)=0.Compute the dot product:(−1)(x)+(3)(y)=0−x+3y=0x=3yChoose the simplest positive value y=1.Then x=3(1)=3.Thus the vector perpendicular to (−1,3) is (3,1).This matches option B.Answer:(3,1), i.e. Option B.