This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
DOPA and 5 - Hydroxytryptophan are clinically
important because 
Select and explain. 
A. They cross Blood Brain Barriers, B. They are acidic precursors of Brain amines, C. They act as neuromodulators, D. They are metabolites of various neurogenic amines
A: They cross Blood Brain Barriers
Answer: A: They cross Blood Brain Barriers 
Explanation: None