None of the square numbers end with _________ at unit’s place.

The correct answer is: 2, 3, 7 or 8

TO FIND-
Which number from the given options cannot be at the unit's place in square of a number.
SOLUTION-
We know that-
Last digit of square of a number = (last digit of the number)²
Last digit of any number (digit at unit's place) will be either of the following- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, whose squares are- 0, 1, 4, 9, 16, 25, 36, 49, 64, 81.
Hence, we can conclude that square of any given number can never end with 2, 3, 7 and 8 as the digit at unit's place.
FINAL ANSWER-
Option 'b' i.e. '2, 3, 7 or 8' is the correct answer to the given question.