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
Lymphocytes and plasma cells 
Select and explain. 
A. Are not normally present in healthy pulp, B. Are associated with injury, C. Attempt to destroy , damage or neutralize foreign substance, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Lymphocytes and plasma cells: 

These cells are not normally present in healthy pulp tissue but are associated with injury and resultant immune responses attempts to destroy, damage, or neutralize foreign substance.
These inflammatory cell types generally appear following invasion into the area of injury.