The correct option is B odd numbers
Any square number can be written as a sum of successive odds.
Ex:
4 = 1+3
9 = 1+3+5
16 = 1+3+5+7
25 = 1+3+5+7+9
We can clearly observe that 1,3,5,7....... are all successive odd numbers and their successive sum starting from 1 results in a square number.