_______ was an important port city in ancient India.

The correct answer is Tamralipti.

Step-by-Step Explanation:

1. Identify the nature of the question: The question asks to identify an important port city in ancient India from the given options.

2. Analyze the options:
- Tamralipti: Located in the modern-day Midnapore district of West Bengal, Tamralipti (often identified with modern Tamluk) was a famous ancient port city situated near the mouth of the Ganges River. It served as a critical hub for maritime trade routes linking ancient India with regions such as Sri Lanka, Southeast Asia (Suvarnabhumi), and East Asia (China).
- Shravasti: Shravasti was an important ancient city located in Uttar Pradesh, associated with the life of Gautama Buddha, but it was an inland capital city of the Kosala kingdom, not a port city.
- Ahichhatra: Ahichhatra was the ancient capital of the Northern Panchala kingdom, located inland in present-day Uttar Pradesh.
- Champa: Champa was the capital of the Anga kingdom, located on the banks of the Ganges River (near modern-day Bhagalpur, Bihar). While it was a river port facilitating inland trade, Tamralipti is historically renowned specifically as the primary international sea trade port of eastern India.

3. Conclusion: Tamralipti is the correct option representing a major, internationally connected ancient Indian port city.