点 $P\left(4,-2\right)$与圆 $x^2+y^2=4$上任一点连续的中点轨迹方程是（）

A．	${\left(x-2\right)}^2+{\left(y+1\right)}^2=1$	B．	${\left(x-2\right)}^2+{\left(y+1\right)}^2=4$
C．	${\left(x+4\right)}^2+{\left(y-2\right)}^2=4$	D．	${\left(x+2\right)}^2+{\left(y-1\right)}^2=1$