若 $\sin (\alpha+\beta)+\cos (\alpha+\beta)=2 \sqrt{2} \cos \left(\alpha+\frac{\pi}{4}\right) \sin \beta$, 则
$\text{A.}$ $\tan (\alpha-\beta)=1$
$\text{B.}$ $\tan (\alpha+\beta)=1$
$\text{C.}$ $\tan (\alpha-\beta)=-1$
$\text{D.}$ $\tan (\alpha+\beta)=-1$