What is the eccentricity of the ellipse if the angle between the straight lines joining the foci to an extremity of the minor axis is 90°?

Consider the following for the next two (02) items that follow :

P(x, y) is any point on the ellipse x² + 4y² = 1. Let E, F be the foci of the ellipse. 

Consider the following for the next two (02) items that follow :

P(x, y) is any point on the ellipse x² + 4y² = 1. Let E, F be the foci of the ellipse. 

Consider the following points :

1. $\left(\frac{\sqrt{3}}{2}, 0\right)$

2. $\left(\frac{\sqrt{3}}{2}, \frac{1}{4}\right)$

3. $\left(\frac{\sqrt{3}}{2},-\frac{1}{4}\right)$

Which of the above points lie on latus rectum of ellipse ?