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
Shadow test is used in 
Select and explain. 
A. Ophthalmoscopy, B. Gonoioscopy, C. Retinoscopy, D. Keratometry
C: Retinoscopy
Answer: C: Retinoscopy 
Explanation: Shadow test in Retinoscopy : Fundal reflex casting shadow in pupillary area.