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: Unknown
Bioavailability of Ramelteon is? 
Select and explain. 
A. 2%, B. 7%, C. 10%, D. 30%
A: 2%
Answer: A: 2% 
Explanation: Reference: Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12th ed., Pg. 1972.
Ramelteon is rapidly absorbed orally, undergoes extensive first pass metabolism in liver, so that bioavailability is low (F = 1.8%) and elimination t½ is 1–3 hours.