If (asecθ, btanθ) and (asecφ, btanφ) be the coordinates of the ends of a focal chord of the hyperbola \(\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1\). then tan θ/2 tan φ/2 =
(a) \(\frac{1 +e}{1 -e}\)
(b) \(\frac{1 -e}{1 +e}\)
(c) \(\frac{e-1}{e+1}\)
(d) None of these