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
In the year 1971 first Pit and Fissure sealant was developed 
Select and explain. 
A. NUVA SEAL., B. NEW SEAL., C. SEALAPEX., D. None
A: NUVA SEAL.
Answer: A: NUVA SEAL. 
Explanation: None