This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Poisoning, Subject name: Forensic Medicine
Speed ball is cocaine plus - 
Select and explain. 
A. Heroin, B. Cannabis, C. Amphetamine, D. LSD
A: Heroin
Answer: A: Heroin 
Explanation: A combination of heroin and cocaine is called as speed balls REF;THE SYNOPSIS OF FORENSIC MEDICINE:KS NARAYANA REDDY;28th EDITION;PAGE NO 347