Equations of the latus rectum of the ellipse $9x^2+4y^2-18x -8y-23=0$ are :

Question

$$\begin {array} {1 1} (a)\;y=\pm \sqrt 5 & \quad (b)\;x=\pm \sqrt 5\\ (c)\;y=1 \pm \sqrt 5 & \quad (d)\;x=-1 \pm \sqrt 5 \end {array}$$