15. These vessels carry low-oxygenated blood to the heart.
O arteries
Oveins
O
aorta

the answer to your question is b

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.