5. In the Cartesian coordinate system, if the equation $m\left(x^{2}+y^{2}+2 y+1\right)=(x-2 y+3)^{2}$ represents an ellipse, then the range of values for $m$ is
A. $(0,1)$
B. $(1,+\infty)$
C. $(0.5)$
D. $(5,+\infty)$