Which of the Following Is the Function of the Blood-Brain

Which of the following is the function of the blood-brain barrier created by glia in the brain?

A) It is an important link between the brain and the hormonal output of the pituitary gland.
B) It opens the bronchi, reduces blood supply to the skin, increases the heart rate, and reduces stomach motility.
C) It regulates the visceral, or involuntary, functions of the body, such as heart rate and blood pressure.
D) It protects the brain from potentially toxic chemicals circulating in the blood.