'A' Is ________; 'B' Is ________

'A' is ________; 'B' is ________.

A) the most recent species to evolve on Earth; an ancestor of group 'A'
B) the most recent species to evolve on Earth; the last common ancestor of Archaea and Eukarya
C) the common ancestor of all life; the common ancestor of Bacteria and Archaea
D) the common ancestor of all life; the last common ancestor of Archaea and Eukarya