The correct answer is: a) Sikkim becoming a British protectorate.
The Treaty of Titalia was signed on 18 November 1817 between the British East India Company and the Kingdom of Sikkim. The treaty was a result of the Anglo-Nepalese War (1814-1816), in which Nepal had invaded Sikkim. The treaty restored some Sikkimese territories previously held by Nepal, but also made Sikkim a British protectorate. This meant that Sikkim was under British control, but retained its own internal government.
The other options are incorrect. Option b) is incorrect because the treaty did not restore all of the Sikkimese territories previously held by Nepal. Option c) is incorrect because Sikkim did not gain any additional territory as a result of the treaty. Option d) is incorrect because the Namgyal dynasty continued to rule Sikkim after the treaty was signed.
The Treaty of Titalia was a significant event in the history of Sikkim. It marked the beginning of British rule in Sikkim and had a major impact on the country’s development.