This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 1, Subject name: Forensic Medicine
The toxic substance responsible for floppy baby syndrome is 
Select and explain. 
A. Lithium, B. Cadmium, C. Antimony, D. Barium
A: Lithium
Answer: A: Lithium 
Explanation: It is seen in newborn babies breastfed by lithium-ingesting mothers due to disruption of afferent inputs from stretch receptors. Manifesting as hypotonicity, lethargy, and cyanosis (floppy baby syndrome).