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: Anaesthesia
Characteristics of Remifentanyl – a) Metabolised by plasma esteraseb) Short half lifec) More potent than Alfentanyld) Dose reduced in hepatic and renal diseasee) Duration of action more than Alfentanyl 
Select and explain. 
A. ab, B. bc, C. abc, D. bcd
C: abc
Answer: C: abc 
Explanation: Remifentanil is the shortest acting opioid due to its metabolism by plasma esterase → dose adjustment is not needed in liver or kidney disease. It is more potent than alfentanil : Order of potency is Sufentanil > Fentanyl = Remifentanil > Alfentanil.