The correct option is A Planaria/Dugesia
Planaria can be cut into pieces and each piece can regenerate into a complete organism. Cells at the location of the wound site proliferate to form a blastema that will differentiate into new tissues and regenerate the missing parts of the piece of the cut planaria. New tissues can grow due to pluripotent stem cells that have the ability to create all the various cell types. These adult stem cells are called neoblasts and comprise 20% or more of the cells in the adult animal. They are the only proliferating cells in the worm and they differentiate into progeny that replace older cells. So, option A is correct.