This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Pharmacology
Low apparent volume of distribution of a drug indicates That 
Select and explain. 
A. Drug has low half life, B. Drug has low bioavailability, C. Drug has low efficacy, D. Drug is not extensively distribution to tissue
D: Drug is not extensively distribution to tissue
Answer: D: Drug is not extensively distribution to tissue 
Explanation: Vd means "the plasma volume that would accommodate all the drug in the body, if the concentration throughout was same as in plasma". Drugs with high volume of distribution are more distributed in body and vice-versa. Low volume of distribution tells that most of the drug is retained in plasma.