Answer:
The correct answer would be option A.
Adult stem cells are the undifferentiated cells present in the human body which keeps dividing and differentiating in order to replenish and repair the damaged and lost cells and tissues.
These cells are derived from the patient's body and after specific differentiation, they are re-introduced into the patient's body.
It decreases the chances of tissue or organ rejection as compared to chances of rejection present with embryonic stem cells.
In contrast, embryonic stem cells are difficult to obtain and specific differentiation of these cells into the cells or tissues of choice is much more complex.
It increases the chances of tissue rejection in the patient due to which high doses of immunosuppressants are used.