The ecentricity of an ellipse $\large\frac{x^2}{a^2}+\frac{y^2}{b^2}$$=1$ whose latus rectum is half to its major axis is e.Find the value of e?

Question

$\begin{array}{1 1}(a)\;\large\frac{1}{\sqrt 2}\\(b)\;\large\frac{1}{\sqrt 3}\\(c)\;\large\frac{1}{\sqrt 5}\\(d)\;\text{None of these}\end{array}$