To answer this question, you need to have knowledge about Tamil literature and the authors of the Periya Puranam.
Option A) Appar - This option is incorrect because Appar, also known as Thirunavukkarasar, is not the author of the Periya Puranam. He was a prominent Tamil saint and one of the 63 Nayanmars, who composed devotional hymns called Thevarams.
Option B) Sundarar - This option is incorrect because Sundarar, also known as Sundaramurthy, is not the author of the Periya Puranam. He was also one of the 63 Nayanmars and composed devotional hymns called Thevarams.
Option C) Kambar - This option is incorrect. Kambar was a Tamil poet who wrote the Ramavataram, which is a Tamil version of the Ramayana. However, he is not the author of the Periya Puranam.
Option D) Sekkizhar - This option is correct. Sekkizhar, also known as Kizhavunar, is the author of the Periya Puranam. The Periya Puranam is an epic Tamil poem that narrates the lives and stories of the 63 Nayanmars. It is considered one of the most important works in Tamil literature.
The correct answer is D) Sekkizhar.