The value of $\cot \left( {\sum\limits_{n = 1}^{19} {{{\cot }^{ - 1}}} \left( {1 + \sum\limits_{p = 1}^n {2p} } \right)} \right)$ is :

Question

${{22} \over {23}}$

${{23} \over {22}}$

${{21} \over {19}}$

${{19} \over {21}}$

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