JEE Advance - Mathematics (2004 - No. 21)
If $${}^{n - 1}{C_r} = \left( {{k^2} - 3} \right)\,{}^n{C_{r + 1,}}$$ then $$k \in $$
$$\left( { - \infty , - 2} \right)$$
$$\left[ {2,\infty } \right)$$
$$\left[ { - \sqrt 3 ,\sqrt 3 } \right]$$
$$\left( {\sqrt 3 ,2} \right]$$