The correct answer is: 1843.
The Portuguese moved the capital of Goa from Old Goa to Panjim in 1843. The move was made due to a number of factors, including the increasing population of Old Goa, which was becoming overcrowded and unsanitary, and the threat of malaria, which was prevalent in the area. Panjim was a more suitable location for the capital, as it was located on the coast and had a more temperate climate.
The move to Panjim was not without its challenges. The city was initially small and underdeveloped, and it took several years for it to become a fully functioning capital. However, the move ultimately proved to be a success, and Panjim has remained the capital of Goa ever since.
Option A: 1840 is incorrect. The Portuguese did not move the capital from Old Goa to Panjim in 1840.
Option B: 1842 is incorrect. The Portuguese did not move the capital from Old Goa to Panjim in 1842.
Option C: 1848 is incorrect. The Portuguese did not move the capital from Old Goa to Panjim in 1848.
Option D: 1843 is correct. The Portuguese moved the capital from Old Goa to Panjim in 1843.