JEE Math Practice Question

An angle of intersection of the curves, $${{{x^2}} \over {{a^2}}} + {{{y^2}} \over {{b^2}}} = 1$$ and x2 + y2 = ab, a > b, is :

1. A.$${\tan ^{ - 1}}\left( {{{a + b} \over {\sqrt {ab} }}} \right)$$
2. B.$${\tan ^{ - 1}}\left( {{{a - b} \over {2\sqrt {ab} }}} \right)$$
3. C.$${\tan ^{ - 1}}\left( {{{a - b} \over {\sqrt {ab} }}} \right)$$
4. D.$${\tan ^{ - 1}}\left( {2\sqrt {ab} } \right)$$