From the question, we have:
P(n) = P(n - 1) + n²
P1 = Po + 1² = 0 + 1 = 1
P2 = P1 + 2² = 1 + 4 = 5 (This is option C)
P3 = P2 + 3² = 5 + 9 = 14 (This is option B)
P4 = P3 + 4² = 14 + 16 = 30 (This is option D)
Therefore the number of snowballs cannot be 25.
So, the correct option is A, which is 25.