Based on the provisional figures of Census 2011 the correct descending order of the four States having the largest population is

The correct answer is (a).

The provisional figures of Census 2011 show that the four states with the largest populations are:

1. Uttar Pradesh (200.3 million)
2. Maharashtra (112.3 million)
3. Bihar (103.8 million)
4. West Bengal (91.3 million)

Therefore, the correct descending order of the four states having the largest population is:

1. Uttar Pradesh
2. Maharashtra
3. Bihar
4. West Bengal

Option (a) is the only option that lists the four states in the correct descending order of population. Option (b) lists the states in the wrong order, with Bihar coming before Maharashtra. Option (c) lists the states in the wrong order, with West Bengal coming before Bihar. Option (d) lists the states in the wrong order, with Maharashtra coming before West Bengal.