Statement 1 is incorrect. Panini was a Sanskrit grammarian who gave a comprehensive and scientific theory of phonetics, phonology, and morphology. Astadhyayi (Astaka) is Panini’s major work. His work is dated around the 3rd-4th century BC. Pushyamitra Shunga on the other hand was the founder and first ruler of the Shunga Empire and ruled around 1st century BC.
Statement 2 is incorrect. Amarasimha was a Sanskrit grammarian and poet from ancient India and was one of the Navratnas during the Gupta dynasty’s rule.
Statement 3 is correct. Kalidasa’s time period in history has varied, depending upon different historians. Several historians believe that Kalidasa belonged to the court of Chandragupta II (Vikramaditya).