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
Eruption of upper canine ahead of upper premolars ; most probable reason being 
Select and explain. 
A. Upper premolars are crowded, B. Upper premolars are impacted, C. Only upper first premolar is impacted, D. Only upper 2nd molar is impacted
A: Upper premolars are crowded
Answer: A: Upper premolars are crowded 
Explanation: None