If $\cos \alpha + \cos \beta = \frac{3}{2}$ and $\sin \alpha + \sin \beta = \frac{1}{2}$ and $\theta$ is the arithmetic mean of $\alpha$ and $\beta$,then $\sin 2\theta + \cos 2\theta$ is equal to

  • A
    $\frac{3}{5}$
  • B
    $\frac{7}{5}$
  • C
    $\frac{4}{5}$
  • D
    $\frac{8}{5}$

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