Concept:The function is a quotient of two differentiable functions, so apply the quotient rule.Explanation:Let y=x+1x.Take u=x and v=x+1.Then dxdu=1 and dxdv=1.Using the quotient rule,dxdy=v2vdxdu−udxdv.Substitute the values:dxdy=(x+1)2(x+1)(1)−x(1).Simplify the numerator:dxdy=(x+1)2x+1−x.Therefore, dxdy=(x+1)21.Answer:The correct option is B: (x+1)21.