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
Which of the following has the maximum faciolingual diameter of the crown: 
Select and explain. 
A. Deciduous maxillary 2nd molar, B. Deciduous maxillary 1st molar, C. Deciduous mandibular 2nd molar, D. Deciduous mandibular 1st molar
A: Deciduous maxillary 2nd molar
Answer: A: Deciduous maxillary 2nd molar 
Explanation: None