The decadal population growth rate of Arunachal Pradesh between 2001-2011 was:

The correct answer is: a) Less than 10%

The decadal population growth rate of Arunachal Pradesh between 2001-2011 was 8.6%. This is lower than the national average of 17.6%. The low population growth rate is due to a number of factors, including a high rate of emigration, a low fertility rate, and a high mortality rate.

Option b) is incorrect because the decadal population growth rate of Arunachal Pradesh between 2001-2011 was 8.6%, which is less than 10%.

Option c) is incorrect because the decadal population growth rate of Arunachal Pradesh between 2001-2011 was 8.6%, which is less than 20%.

Option d) is incorrect because the decadal population growth rate of Arunachal Pradesh between 2001-2011 was 8.6%, which is less than 30%.