Which of the following statement(s) is/are correct about Alvars and Nayanars?
I. Some of the earliest bhakti movements (c. sixth century) were led by the Alvars (literally, those who are "immersed" in devotion to Vishnu) and Nayanars (literally, leaders who were devotees of Shiva).
II. They travelled from place to place singing hymns in Tamil in praise of their gods.
III. During their travels the Alvars and Nayanars identified certain shrines as abodes of their chosen deities