The correct answer is C. 999.
The sex ratio of Scheduled Tribes in Himachal Pradesh is 999, which means that there are 999 females for every 1000 males. This is higher than the national average of 940, and it is also higher than the sex ratio of Scheduled Tribes in other states.
There are a number of factors that may contribute to the high sex ratio of Scheduled Tribes in Himachal Pradesh. One possibility is that there is a strong cultural preference for sons in this state. Another possibility is that there is better access to healthcare and education for girls in Himachal Pradesh, which may lead to lower rates of female infanticide and child mortality.
Whatever the reasons, the high sex ratio of Scheduled Tribes in Himachal Pradesh is a positive development. It suggests that the state is making progress in terms of gender equality, and it is likely to have a number of benefits for the state’s economy and society in the long run.
Option A is incorrect because the sex ratio of Scheduled Tribes in Himachal Pradesh is not 1,015.
Option B is incorrect because the sex ratio of Scheduled Tribes in Himachal Pradesh is not 890.
Option D is incorrect because the sex ratio of Scheduled Tribes in Himachal Pradesh is not 900.