Any tangent at a point $P(x, y)$ to the ellipse $\frac{x^{2}}{8}+\frac{y^{2}}{18}=1$ meets the co-ordinate axes in the points $A$ and $B$ such that the area of the triangle $O A B$ is least, then the point $P$ is
(a) $(\sqrt{8}, 0)$
(b) $(0, \sqrt{18})$
(c) $(2,3)$
(d) None