This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Pharmacology, Subject name: Pharmacology
[{'content': 'After oral administration the fraction of drug reaching the systemic circulation in unchanged form is: \nSelect and explain. \nA. Elimination, B. Distribution, C. Bioavailability, D. Metabolism', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (Ref: KD Tripathi, 7th ed. pg. 16)BIOAVAILABILITYBioavailability is a measure of the fraction of administered dose of a drug that reaches the systemic circulation in the unchanged form.Bioavailability of drug injected IV is 100%, but isfrequently lower after oral ingestion because--#The drug may be incompletely absorbed.#The absorbed drug may undergo first pass metabolism in the intestinal wall/liver or be excreted in bile.', 'role': 'assistant'}]