The correct answer is: Kullu.
The sex ratio in Kullu district is 1080 females per 1000 males, which is the highest among all the districts of Himachal Pradesh. The sex ratio in Kangra district is 1064 females per 1000 males, the sex ratio in Hamirpur district is 1052 females per 1000 males, and the sex ratio in Mandi district is 1045 females per 1000 males.
There are a number of factors that contribute to the high sex ratio in Kullu district. One factor is that the district has a strong tradition of female education. The literacy rate for women in Kullu district is 82%, which is higher than the national average of 65%. Another factor is that the district has a strong economy, which provides employment opportunities for both men and women. This helps to reduce the gender gap in employment and income. Finally, the district has a relatively egalitarian social structure, which values the contributions of both men and women.
The high sex ratio in Kullu district is a positive sign for the future of the district. It suggests that the district is on track to achieve gender equality, which is essential for sustainable development.