The smallest positive angle which satisfies the equation $2{\sin ^2}\theta + \sqrt 3 \cos \theta + 1 = 0$, is

  • A

    $\frac{{5\pi }}{6}$

  • B

    $\frac{{2\pi }}{3}$

  • C

    $\frac{\pi }{3}$

  • D

    $\frac{\pi }{6}$

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