This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Drug Abuse, Subject name: Forensic Medicine
Heavy user of LSD is called as 
Select and explain. 
A. Acid head, B. Guide, C. Main liner, D. Tripper
A: Acid head
Answer: A: Acid head 
Explanation: Acid head - Heavy user of LSD Guide - a person who babysits for a psychedelic user during a session. Mainlining: injecting drug into IV. A common pattern of LSD use is trip (occasional use followed by a long period of abstinence). But Not Tripper.