Option a is the correct answer. Basavanna, also known as Basava or Basaveshwara, was the founder of the Virashaiva Movement in Karnataka. This 12th-century philosopher, social reformer, and poet initiated a socio-religious movement that aimed to challenge and reform the prevailing social and religious practices of the time. Basavanna emphasized social equality, rejected caste-based discrimination, and promoted spiritual enlightenment through personal experience rather than rigid rituals.