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
Immature senile cataract can be best differentiated from mature senile cataract by: 
Select and explain. 
A. Iris shadow test, B. Oblique illumination examination, C. Visual acuity testing, D. Distant direct ophthalmoscopy
D: Distant direct ophthalmoscopy
Answer: D: Distant direct ophthalmoscopy 
Explanation: Ans. Distant direct ophthalmoscopy