Indian Institute of Foreign Trade 2012 Solved Paper

The given series is a combination of 3 series:-
1st containing all 3n+1 terms i.e. 1st, 4th, 7th and so on terms:-
-1, 0, 1, 2 and thus, the next number will be 3.
2nd containing all 3n+2 terms i.e. 2nd, 5th, 8th and so on terms:-
0, 2, 6, 12 as we can see 2n is being added to each term to get the next term and thus the next term will be 20.
3rd containing all 3n terms i.e. 3rd, 6th, 9th and so on terms:-
1, 4, 9, 16 an we can see these are squares of the natural numbers and thus, the next term will be 25.
Hence, ?,?,? will be 3, 20, 25
Hence, option C is the correct answer.