Option a is the correct answer. Samudragupta was a great conqueror who carried his sword throughout the length and breadth of India and built the mighty Gupta Empire. He annexed a large number of kingdoms in Aryavarta to the Gupta Empire and defeated at least twelve kings of South India. He was given the title of 'Prithivyah Pratham Veer', which means the first powerful man of the world. At a pillar in Allahabad, the details of the wars he fought are described.