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
Lead time is defined is - 
Select and explain. 
A. Time between diagnosis and treatment, B. Time between point where the diagnosis is made by screening test to usual diagnosis., C. Time between disease onset and outcome, D. Time between usual time of diagnosis and outcome.
B: Time between point where the diagnosis is made by screening test to usual diagnosis.
Answer: B: Time between point where the diagnosis is made by screening test to usual diagnosis. 
Explanation: Ans. is 'b' i.e., Time between point where the diagnosis is made by screening test to usual diagnosis