${ }^{n-1} C_r=\left(k^2-8\right){ }^n C_{r+1}$ if and only if :

Question

$2 \sqrt{2}<\mathrm{k}<2 \sqrt{3}$

$2 \sqrt{2}<\mathrm{k} \leq 3$

$2 \sqrt{3}<\mathrm{k}<3 \sqrt{3}$

$2 \sqrt{3}<\mathrm{k} \leq 3 \sqrt{2}$

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