3. The locus of the center of a circle that is tangent to the $x$-axis and externally tangent to the circle $x^{2}+y^{2}=1$ is
(A) $x^{2}=2 y+1$
(B) $x^{2}=-2 y+1$
(C) $x^{2}=2|y|+1$
(D) $x^{2}=2 y-1$
$C$