The correct option is B The twelve Alvars were Tamil poet-saints, who lived between 6th and 9th centuries AD and espoused 'emotional devotion' or bhakti to Vishnu-Krishna in their songs.
The earliest bhakti movements (from sixth
century to ninth century) were led by the 12 Alvars. These Alvars were“immersed” in devotion to Vishnu or Krishna.