8. The polar equation of a circle is $\rho=\sqrt{2}(\cos \theta+\sin \theta)$, the coordinates of the center of the circle are ( ).
A. $\left(2, \frac{\pi}{4}\right)$
B. $\left(1, \frac{\pi}{4}\right)$
C. $\left(1, \frac{3 \pi}{4}\right)$
D. $\left(\sqrt{2},-\frac{\pi}{4}\right)$