Explanation:

- Chandragupta Vikramaditya: A prominent ruler of the Gupta Empire, known for literature and arts, but not associated with the earliest classical Sanskrit inscriptions.

- Kanishka I: A Kushan emperor, famous for spreading Buddhism, and inscriptions are generally in mixed languages like Bactrian, Greek, and Sanskrit.

- Rudradaman: The correct answer! He was a ruler of the Western Kshatrapas and is known for the Junagarh Rock Inscription, which is the earliest long inscription in classical Sanskrit.

- Samudragupta: Another Gupta emperor, renowned for conquests and cultural achievements, but does not hold the record for the first major Sanskrit inscription.