The correct answer is: 973.
The Scheduled Castes sex ratio of Himachal Pradesh is 973, which means that there are 973 females for every 1000 males. This is higher than the national average of 940, and it is also higher than the sex ratio of the Scheduled Castes in other states. This is likely due to the fact that Himachal Pradesh is a relatively developed state with a high literacy rate and a good healthcare system. These factors contribute to a better quality of life for all residents of the state, including the Scheduled Castes.
Option A: 963 is incorrect because it is lower than the actual sex ratio of 973.
Option B: 983 is incorrect because it is higher than the actual sex ratio of 973.
Option C: 978 is incorrect because it is not one of the options given.
Option D: 973 is the correct answer because it is the actual sex ratio of the Scheduled Castes in Himachal Pradesh.