This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Causes for reduced bioavailability include 
Select and explain. 
A. high first pass metabolism, B. increased absorption, C. high lipid solubility, D. non ionization
A: high first pass metabolism
Answer: A: high first pass metabolism 
Explanation: Ref-KDT 7/e p18 the causes of low availability are reduced absorption highfirst pass metabolism