This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
There are some undesirable but unavoidable pharmacodynamic effects of a drug, which are known as: 
Select and explain. 
A. Toxic effects, B. Idiosyncrasy, C. Side effects, D. Intolerance
C: Side effects
Answer: C: Side effects 
Explanation: None