Which of these is the BEST source of stem cells and minimizes the risk associated with stem cell transplantation?(Please Help!!)

Select one:
a. Stem cells from rejected grafts that initiated an immune response.
b. Stem cells preserved from the umbilical cord of the person.
c. Stem cells from a donor having the same blood group.
d. Stem cells from a donor who is the same age as the patient.

B. Stem cells preserved from the umbilical cord of the person.

Explanation:

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.