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
A male 45 years old presents to the dental clinic with pain in lower back tooth region. Intraoral examination reveals carious 36. Root canal treatment done and Zirconia crown has to be placed. Dentist makes an impression with polysulfide impression material.
This material has the working time(in minutes): 
Select and explain. 
A. 7-Apr, B. 2.5 - 4, C. 4-Feb, D. 3
A: 7-Apr
Answer: A: 7-Apr 
Explanation: Key concept: Polysulfides have the longest working time of the elastomeric impression materials i.e. 4-7 minutes.
Comparative Properties of Elastomeric Impression Materials