What is one bioethical concern regarding stem-cell therapy?

a. it is expensive and only available to the wealthy.
b. stem cells could cause unknown types of diseases.
c. stem cells cannot be taken from the patient's body, requiring a bone-marrow donor.
d. organs created by a patient's stem cells could be rejected by the patient's body.

Andrew feels good about himself. he doesn't know exactly why he is so happy, but every day he looks forward to his schoolwork and chores. "i play a game," he says. "i make a list of everything i have to get done, and then i try to finish it all before a certain time. for some reason, i feel great when i beat my time." based on this information, why is andrew happy? he gets a proper amount of sleep he eats healthy meals he has a strong family support group he regularly meets his own goals