The reason for the answer "4. A, D only" is based on historical facts related to the Tamil saints and poets who composed the "Tevaram" hymns. Here's the breakdown:

Sundarar and Appar: Sundarar and Appar were two of the prominent poets of the "Tevaram." They lived during the 7th to 9th century and are well-known for their contributions to the collection of "Tevaram" hymns.

Sambandar: Sambandar was another significant poet of the "Tevaram" during the same period as Sundarar and Appar, i.e., in the 7th to 9th century. He is one of the trio of saints/poets who are collectively known as the Nayanars and made substantial contributions to Tamil Shaiva devotional literature.

So, the correct option is [4].