The correct answer is option B) Barbaricum.

During the pre-Gupta age, the Indus delta had several ports that played a significant role in maritime trade. One of these ports was Barbaricum, located on the Indus delta in present-day Pakistan. Let's explore more about Barbaricum and why it was an important port during that period.

**1. Barbaricum:**
- Barbaricum was a flourishing port city located on the Indus delta, which is formed by the confluence of the Indus River and the Arabian Sea.
- It was an important center for international trade in the Indian Ocean region during the pre-Gupta age.
- The port served as a hub for maritime trade between the Indian subcontinent, the Persian Gulf, and the Roman Empire.
- It was strategically located at the mouth of the Indus River, which made it an ideal port for trade with the inland regions of the Indian subcontinent.
- Barbaricum was known for its trade in various commodities, including textiles, spices, precious stones, and metals.
- The port also facilitated the exchange of ideas, culture, and technology between different civilizations.

**2. Other Ports:**
- Barygaza (also known as Bharuch) was another port that was located on the western coast of India, near the mouth of the Narmada River. It was an important trade center during the ancient and medieval periods.
- Muziris (also known as Muchiri) was a famous port city on the Malabar Coast (present-day Kerala). It was a major center for spice trade, particularly with the Roman Empire.
- Korkai was a port city located on the east coast of India, near the mouth of the Tamiraparani River. It was an important center for trade in pearls and other marine products.

**3. Significance of Barbaricum:**
- Barbaricum gained prominence due to its strategic location and its role in facilitating trade between different regions.
- The port attracted merchants from various parts of the world, leading to the growth of a cosmopolitan society.
- The trade conducted through Barbaricum contributed to the economic prosperity of the region and helped in the exchange of goods and ideas.
- The port's significance declined in the subsequent centuries due to factors like changes in trade routes and political upheavals.

In conclusion, Barbaricum was the port located on the Indus delta during the pre-Gupta age. It played a crucial role in facilitating maritime trade and cultural exchange in the Indian Ocean region.