If $\tan \theta = - \frac{1}{{\sqrt {10} }}$ and $\theta $ lies in the fourth quadrant, then $\cos \theta = $

  • A

    $1/\sqrt {11} $

  • B

    $ - 1/\sqrt {11} $

  • C

    $\sqrt {\frac{{10}}{{11}}} $

  • D

    $ - \sqrt {\frac{{10}}{{11}}} $

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