This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 3, Subject name: Forensic Medicine
The following plant contains the toxic substance- 
Select and explain. 
A. Atropine, B. Cannabis, C. Ricin, D. Oxalic acid
D: Oxalic acid
Answer: D: Oxalic acid 
Explanation: The plant is Indian spinach, which contains oxalic acid(image given) oxalic acid --> stomach-->blood-->Hypocalcemia Treatment is IV calcium.