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: Social & Preventive Medicine
A patient with cervix cancer is missed by a screening test and later diagnosed with advanced disease. This time interval is called ? 
Select and explain. 
A. Lead time, B. Screening time, C. Serial interval, D. Generation time
A: Lead time
Answer: A: Lead time 
Explanation: Ans. is 'a' i.e. Lead time