Solution:

The correct answer is option 'D', which means both (b) Nayanars and (c) Alvars. Let's understand each of these options in detail.

1. Sufis:
Sufis were Islamic mystics who practiced Sufism, a mystical form of Islam. They focused on the inner, spiritual aspects of Islam and sought a direct experience of the divine. Sufis were known for their devotion and love for God, and they often expressed their spirituality through poetry and music. However, the given statement specifically mentions composing poems in praise of deities, which aligns more with the practices of Hindu saints.

2. Nayanars:
Nayanars were a group of Tamil Shaivite saints who lived in South India during the medieval period. They were devotees of Lord Shiva and composed devotional poems known as Thevaram in praise of the deity. The Nayanars traveled from place to place, visiting Shiva temples and spreading the message of devotion. Their poems were not just literary works but were considered sacred texts in the Tamil Shaivite tradition.

3. Alvars:
Alvars were a group of Tamil Vaishnavite saints who also lived in South India during the medieval period. They were devotees of Lord Vishnu and composed devotional poems known as Divya Prabandham in praise of the deity. Similar to the Nayanars, the Alvars traveled from village to village, visiting Vishnu temples and spreading the message of devotion. Their poems were highly regarded and became an integral part of the Tamil Vaishnavite tradition.

Conclusion:
Both the Nayanars and Alvars were saints who composed exquisite poems in praise of the deities enshrined in the villages they visited. While the Nayanars focused on Lord Shiva and composed Thevaram, the Alvars focused on Lord Vishnu and composed Divya Prabandham. Therefore, the correct answer is option 'D' - both (b) Nayanars and (c) Alvars.