Answer: <u>Intrinsic</u> should be the correct answer.
They can constrict or dilate because their walls are muscular.
A system in which medical doctors and other healthcare professionals (such as nurses, pharmacists, and therapists) treat symptoms and diseases using drugs, radiation, or surgery. Also called allopathic medicine, biomedicine, conventional medicine, mainstream medicine, and orthodox medicine.
Answer:
B
Explanation:
Bro you can answer that question on google
