The ruler of Bhavnagar signed the Instrument of Accession first among all the states within the region.
The Instrument of Accession was a document signed by the rulers of princely states in India in the years leading up to and following Indian independence in 1947. The document gave the rulers the choice of either joining the newly independent Dominion of India or remaining independent. The majority of rulers chose to join India, and the Instrument of Accession was the legal instrument by which they did so.
The ruler of Bhavnagar, Maharaja Khengarji III, was the first to sign the Instrument of Accession on August 15, 1947. His decision was followed by the rulers of other princely states, and by the end of 1947, all but a handful of princely states had acceded to India.
The Instrument of Accession was a significant step in the process of Indian independence. It marked the end of the British Raj and the beginning of a new era for India. It also paved the way for the integration of the princely states into the Indian Union.
The other options are incorrect because they were not the first princely states to sign the Instrument of Accession. Baroda signed the Instrument of Accession on August 18, 1947, Nawanagar signed on August 19, 1947, and Wankaner signed on August 20, 1947.