In following questions, one term in number series is incorrect. - Find out the incorrect number 1236, 2346, 3456, 4566, 5686

Answer: D. 5686

The first digits of the numbers from the series 1, 2, 3, 4, 5;
the second digits from the series 2, 3, 4, 5,6;
the third digits from the series 3, 4, 5, 6;
while the last digit in each of the numbers is 6.
So, 5686 is wrong and must be replaced by 5676.