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: Microbiology
Streptococcal pneumoniae presents at 
Select and explain. 
A. <5 years, B. 5-15 years, C. 20-25 years, D. 30-40 years
A: <5 years
Answer: A: <5 years 
Explanation: → Streptococcus pneumoniae is the leading cause of pneumonia, both lobar and bronchopneumonia.
→ Pneumonia is common at the extreme of ages:

Children (especially >5 years of age)
Elderly (>60 - 65 years)

→ Serotypes 6, 14, 18, 19 and 23 are responsible for most cases of pneumonia in children, while serotypes 1, 3, 4, 7, 8 and 12 cause pneumonia in adults.