The famous Tamil epic composed by Ilango Adigal is:

The famous Tamil epic "Silappadikaram" ("The Tale of the Anklet") was composed by Ilango Adigal, around 1,800 years ago (some scholars date it to the 5th-6th century CE).

About Ilango Adigal:

• According to tradition, he was a prince of the Chera dynasty, and the younger brother of the Chera king Senguttuvan, who became a Jain (or Buddhist) monk.
• "Adigal" means a revered ascetic.

About the Silappadikaram:

• It is one of the "Five Great Epics" (Aimperumkappiyangal) of Tamil literature.
• It tells the story of Kovalan, a rich merchant of Puhar (Kaveripattinam), his devoted wife Kannagi, and the dancer Madhavi.
• Kovalan leaves Kannagi for Madhavi, loses his wealth, and later returns to Kannagi.
• They go to Madurai to start a new life; Kovalan tries to sell one of Kannagi's anklets (silambu).
• He is falsely accused of stealing the queen's anklet, and is executed on the orders of the Pandya king.
• Kannagi proves his innocence by breaking her anklet, which contains rubies, while the queen's anklet contains pearls.
• The Pandya king dies of shame, and Kannagi, in her anger, burns the city of Madurai.
• Kannagi is later worshipped as a goddess of chastity ("Pattini").
• Its three books are named after the three Tamil kingdoms: Puhar (Chola), Madurai (Pandya) and Vanji (Chera).
• NCERT mentions the Silappadikaram as a famous Tamil epic, and describes the story of Kovalan.

The Five Great Epics of Tamil:

• Silappadikaram (Ilango Adigal).
• Manimekalai (Sittalai Sattanar): a sequel, about Manimekalai, the daughter of Kovalan and Madhavi, who becomes a Buddhist nun.
• Jivaka Chintamani (Tiruttakkatevar): a Jain epic.
• Valayapathi and Kundalakesi (partly lost).

Other Tamil works:

"Tirukkural": by Tiruvalluvar, a collection of 1,330 couplets on virtue, wealth and love.

Why not the other options?

• ✗Manimekalai was written by Sittalai Sattanar.
• ✗Jivaka Chintamani was written by Tiruttakkatevar.
• ✗Tirukkural was written by Tiruvalluvar.