The birth of "Dolly the Sheep" proved ( ).

A、Differentiated mammalian cells still have "totipotency";

B、Plants have stronger regeneration ability than animals, and lower organisms have stronger regeneration ability than higher organisms;

C、Differentiated cells can lose their original structural functions through dedifferentiation, transform into cells with undifferentiated characteristics, and differentiate into another cell type through cell proliferation, and even form new individuals.;

D、Although the differentiation potential of cells gradually loses during development, from a genetic point of view, the totipotency of the nucleus has not been lost.