here in this question, its given that n is an integer and n is between 2 and 100. Also n is the square of an integer.
Now statement 1 => n is even therefore n could be 4, 16, 36, 64.
Not sufficient.
Take statement 2 => n=64 . n is square of 8 and its cube root is 4. This is the only value that satisfy the conditions and thus is unique. Hence sufficient.
B is the correct answer.
Hope this helps!!