* Statement 1 is incorrect: Devichandraguptam is attributed to Vishakhadatta, a Sanskrit playwright. Bilhana was a poet who lived much later.  * Statement 2 is correct: Hammira-Mahakavya was written by Nayachandra Suri, a Jain scholar and poet. * Statement 3 is incorrect: Milinda-Panha is a dialogue between Buddhist philosopher Nagasena and Indo-Greek King Milinda, focusing on Buddhist concepts like non-self (anatta) and nirvana. Nagasena belonged to the Hinayana tradition, while Nagarjuna, often confused with him, was a Mahayana scholar. For clarity in UPSC, refer to the Milinda-Panha philosopher as Nagasena. * Statement 4 is correct: Nitivakyamrita was written by Somadeva Suri. Thus, statements 2 and 4 are correct.