The exponent of Vaisheshika Darshan (philosophy) is Kanad. Vaisheshika Darshan is one of the six classical Indian philosophical schools. It was founded by the sage Kanad, who is also known as Kashyapa. Vaisheshika Darshan focuses on the study of metaphysics and atomism, and it provides a detailed analysis of the nature of reality and the nature of objects. Kanad`s teachings in Vaisheshika Darshan revolve around the concept of atoms and the categorization of substances and their qualities. It is important to note that while Kapil and Akshapad Gautam were also philosophers, they are associated with different philosophical schools (Samkhya and Nyaya respectively). Therefore, the correct answer is option 3, Kanad.