Final answer:
Increased trade in the Indian Ocean led to diplomatic and military alliances between the Portuguese and the local Hindu kings of southern India. Correct option is A.
Step-by-step explanation:
The excerpt from the Portuguese messenger's speech suggests that increased trade in the Indian Ocean had the effect of leading to diplomatic and military alliances. The messenger mentions that the King of Portugal desires to render honour and service to the Gentile Kings of India, and that he is prepared to help them with fleets and armies. This implies that increased trade created political relationships between the Portuguese and the local Hindu kings, resulting in alliances and cooperation.
Increased trade during this period led to the establishment of diplomatic and military alliances, particularly evident in the Portuguese efforts to dominate Indian Ocean trade by aligning with some Indian rulers and using military force.
The conclusion about the effects of increased trade supported by the above excerpt is that increased trade led to diplomatic and military alliances. This is evident from the Portuguese desire to establish strategic partnerships with local rulers against their common enemies, the Ottomans and Arabs, who were competing for control over the Indian Ocean trade routes. The Portuguese, represented by the messenger, express their readiness to align militarily with the Hindu king, expecting reciprocal support in terms of troops, harbors, and other resources necessary for commerce and war. Moreover, the historical context shows that the Portuguese aimed to dominate trade in the Indian Ocean and did so by forming alliances with some Indian rulers, as well as by using force to seize control of key ports and trading routes, further emphasizing the connection between increased trade and the formation of alliances for economic and strategic advantages.