Recognize the Paraneoplastic Neurological Syndromes associated with Small Cell Lung Cancer and their associated Antibodies

A 45-year-old man chronic smoker having 25 pack years history of smoking presented with involuntary shaking of his hands, arms, legs and trunks associated with blurring of vision and difficulty in seeing objects for last 2 weeks. He denied any numbness or weakness of any part of his body. He was otherwise fit and well apart for occasional shortness of breath and cough that he attributed to long term smoking. Clinical examination revealed conjugate, randomly directed, rapid eye movements and by Myoclonus occurring in the face, head/neck, trunk, and limbs. He also exhibited Cerebellar Dysfunction with Dysarthria and Truncal Ataxia. He underwent biochemical and metabolic panel followed by MRI brain with Gadolinium enhancement that turned out to be unremarkable. Chest radiograph showed right side hilar prominence for which he underwent CECT chest followed by biopsy of the enlarged right sided hilar lymph node and it showed SCLC. Keeping in view the diagnosis of Opsoclonu Myoclonus Ataxia (OMA), one of the Paraneuplastic Neurological syndromes

Which of the following is the most frequently occurring antibody in this condition?