已知一动圆与圆C₁: x²+y²+2x-4y+1=0外切，并且和定圆C₂: x²+y²-10x-4y-71=0内切，求动圆圆心的的轨迹方程。

________that Maric was able to set up new branches elsewhere.      

A．So successful her business was

B．So successful was her business

C．So her business was successful

D．So was her successful business