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
Which test helps to differentiate between concomitant squint and paralytic squint 
Select and explain. 
A. Cover - uncover test, B. Alternate covertest, C. Direct cover test, D. None of the above
B: Alternate covertest
Answer: B: Alternate covertest 
Explanation: This procedure causes breakdown of binocular fusion mechanism thus helpful to differentiate.