The correct answer is option 2, which is 2 3 - 2 - 1 - 4.

To arrange the states in decreasing population size, we need to refer to the census data from 2011. According to the census, the states with the highest population size are as follows:

1. Uttar Pradesh

2. Maharashtra

3. Bihar

4. West Bengal

Looking at the options provided:

Option 1: Uttar Pradesh is not included in the options, so this is not the correct answer.

Option 2: Maharashtra is ranked correctly as the second state with the highest population. Bihar is ranked third, and West Bengal is ranked fourth. This is the correct answer.

Option 3: West Bengal is ranked first, which is incorrect.

Option 4: Andhra Pradesh is ranked first, which is incorrect.

In conclusion, the correct answer is option 2, with the arrangement 2 3 - 2 - 1 - 4.