The correct answer is (a) 20 females per 1000 males.
The sex ratio in Uttar Pradesh improved from 912 females per 1000 males in 2001 to 932 females per 1000 males in 2011. This means that there were 20 more females per 1000 males in 2011 than in 2001.
There are a number of factors that could have contributed to this improvement in the sex ratio. One possibility is that there has been a decrease in the practice of female infanticide. Another possibility is that there has been an increase in the awareness of the importance of girls’ education. Whatever the reasons, the improvement in the sex ratio is a positive development for the state of Uttar Pradesh.
Option (b) is incorrect because the sex ratio in Uttar Pradesh improved by 20 females per 1000 males, not 10 females per 1000 males.
Option (c) is incorrect because the sex ratio in Uttar Pradesh improved by 20 females per 1000 males, not 60 females per 1000 males.
Option (d) is incorrect because the sex ratio in Uttar Pradesh improved by 20 females per 1000 males, not 40 females per 1000 males.