This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
The magnification obtained by direct ophthalmoscope is 
Select and explain. 
A. 5times, B. 10times, C. 15times, D. 20times
C: 15times
Answer: C: 15times 
Explanation: TECHNIQUE MAGNIFICATION FIELD OF VIEW CHARACTERISTICS Direct ophthalmoscopy 15X 5* Erect and viual Indirect ophthalmoscopy with +20D 3X 45* Inveed reversed and real Indirect ophthalmoscopy with +30D 2X 50* Inveed reversed and real Biomicroscopic examination with +78D 10X 30* Inveed reversed and real Biomicroscopic examination with +90D 7.5X 40* Inveed reversed and real Fundus camera 2.5X 30* Erect, viual, photo documentation Ref. : Khurana's Theory and Practice of Optics and Refraction; 2nd Ed; Pg. 386