Answer: The city that established itself as a major shipping power is d. Pisa.
Step-by-step explanation:
Pisa is a city located in the Tuscany region of Italy, and during the High Middle Ages, it established itself as a major shipping power. Pisa was strategically located on the coast, making it an ideal location for maritime trade, and the city's naval fleet played a significant role in its rise to power. Pisa's location on the Arno River also made it an important center for agriculture and trade, as goods from the surrounding areas were transported to the city for export. The city's famous Leaning Tower of Pisa is a testament to its architectural and engineering achievements, which were fueled by the city's wealth and power.
Hence, The correct option is D