3. The complex number $z$ satisfies $z+\frac{1}{z} \in \mathbf{R}$, and $|z-2|=\sqrt{2}$, then the number of such complex numbers $z$ is
A. 1
B. 2
C. 3
D. 4
3. D $z+\frac{1}{z}=\bar{z}+\frac{1}{\bar{z}},(z-\bar{z})\left(1-\frac{1}{z \bar{z}}\right)=0,|z-2|=\sqrt{2} \quad$ so $z \in \mathbf{R},|z|=1$