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
In retinoscopy for refractive error at 1m, we add 1D ; if done at a distance of 66 cm, the additional factor will be – 
Select and explain. 
A. –2, B. –1.5, C. –0.5, D. –5
B: –1.5
Answer: B: –1.5 
Explanation: Deduction of 1D for lm and 1.5D when retinoscopy is performed at 2/3rd m (67 cm) distance.