which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells? a. embryonic stem cells only differentiate into only eggs and sperm, and adult stem cells differentiate into any type of cell. b. embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot. c. embryonic stem cells can continue to reproduce for an indefinite period, and adult stem cells cannot. d. one aim of using embryonic stem cells is to provide cells for repair of diseased tissue.