This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Regional Anesthesia, Subject name: Anaesthesia
Which of the following local anaesthetic causes least vasodilation: 
Select and explain. 
A. Bupivacaine, B. Prilocaine, C. Ropivacaine, D. Lignocaine
B: Prilocaine
Answer: B: Prilocaine 
Explanation: Prilocaine causes less vasodilation than other local anesthetics and thus used without using epinephrine added to the local anesthetic solution.