The tactics the East India Company (EIC) employed to monopolize trade in India primarily include:
B. Exclusive use of British soldiers to prevent local Indians from being armed
C. Invasion of the Interior regions of India to access the natural resources
D. Loans and Military Support to local nawabs in exchange for trade compromises
Among these options, A (Creation of port cities that allowed European nations to freely trade in the region) is not a tactic used by the EIC. Instead, they often sought to limit competition by weakening or overpowering other European traders and local powers.
In summary, B, C, and D reflect the strategies used by the EIC to establish and maintain its dominance in India.