With reference to the period of Gupta dynasty in ancient India, the towns Ghantasala, Kadura and Chaul were known as

The correct option is ports handling foreign trade.

During the Gupta period (circa 4th to 6th century CE), ancient India witnessed a significant expansion in maritime trade and commerce, both with the Roman Empire to the west and Southeast Asian countries to the east.

Ghantasala and Kadura (located in the present-day Andhra Pradesh region along the eastern coast) and Chaul (located near present-day Mumbai in Maharashtra on the western coast) served as important port towns and trade hubs.
These ports handled the export and import of various goods, including spices, pearls, precious stones, silks, and perfumes, facilitating active cultural and economic exchanges between the Indian subcontinent and foreign empires.