Explanation:

The Arjuna Award is indeed a national sports award in India, instituted in 1961 to recognize outstanding achievement in national sports. Option (1) 'OTT award' is not a recognized national sports award; 'OTT' typically refers to 'Over-The-Top' media services. Option (3) 'Abel Prize' is an international prize awarded annually by the King of Norway to one or more outstanding mathematicians, not a sports award. Option (4) 'Vatayan Lifetime Achievement Award' is an award given in the field of literature and arts, not sports. Thus, only the Arjuna Award is a national sports award among the given options.