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: Dental
Eugenol in a periodontal dressing could cause 
Select and explain. 
A. allergic reaction, B. decreased resistance to heat, C. rapid bacterial growth, D. all of the above
A: allergic reaction
Answer: A: allergic reaction 
Explanation: None