This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
Time period between entry of organism to body to maximum infectivity is - 
Select and explain. 
A. Lead time, B. Median incubation period, C. Generation time, D. Serial inverval
C: Generation time
Answer: C: Generation time 
Explanation: Ans is 'c' i.e., Generation time * Generation time - Period from receipt of infection to maximal infectivity.* Serial interval - Gap between onset of primary case and secondary case.