This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ocular motility and squint, Subject name: Ophthalmology
Disscociated veical detion seen in - 
Select and explain. 
A. AV dissociation, B. Infantile esotropia, C. Congenital esotropia, D. Superior oblique palsy
B: Infantile esotropia
Answer: B: Infantile esotropia 
Explanation: Infantile esotropia, previously called as congenital esotropia, is characterised by following features : Age of onset, 1-2 months of age. Angle of detion- constant and large Fixation pattern. Binocular vision does not develop and there is alternate fixation in primary gaze and cross fixation in the lateral gaze. Amblyopia Associations includes inferior oblique overaction, dissociated veical detion (DVD) in about 70-90 % cases, and lateral horizontal nystagmus. Ref : A.K.Khurana; 6th edition; Page no: 348