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: Ophthalmology
The posterior focal point of the reduced eye situated on the retina is how many millimetre behind the anterior surface of cornea: 
Select and explain. 
A. 22.9 mm, B. 24.4 mm, C. 23 mm, D. 21 mm
B: 24.4 mm
Answer: B: 24.4 mm 
Explanation: Ans. 24.4 mm