If the length of the major axis intercepted between the tangent and normal at a point `P (a cos theta, b sin theta)` on the ellipse `(x^(2))/(a^(2)) +(y^(2))/(b^(2)) =1` is equal to the length of semi-major axis, then eccentricity of the ellipse is
A. `(cos theta)/(sqrt(1-cos theta))`
B. `(sqrt(1-cos theta))/(cos theta)`
C. `(sqrt(1-cos theta))/(sin theta)`
D. `(sin theta)/(sqrt(1-sin theta))`