Explanation:

1. Panini is associated with Pushyamitra Shunga: Incorrect. Panini, the ancient Indian grammarian known for his work "Ashtadhyayi", lived much before Pushyamitra Shunga. Panini is generally dated to the 5th or 6th century BCE, whereas Pushyamitra Shunga lived in the 2nd century BCE.
2. Amarsimha is associated with Harshavardhana: Incorrect. Amarsimha, the author of "Amarakosha", a famous Sanskrit dictionary/thesaurus, is traditionally associated with the Gupta period, particularly with the court of Chandragupta II. Harshavardhana lived a few centuries later, in the 7th century CE.
3. Kalidasa is associated with Chandragupta II: Correct. Kalidasa, one of the greatest Sanskrit poets and playwrights, is traditionally believed to have lived during the reign of Chandragupta II, in the Gupta Empire. He is often considered as one of the "nine gems" (Navaratnas) of the Gupta court.