If all the even digits are changed to the next digit whereas all odd digits are changed to the previous digit in the

If all the even digits are changed to the next digit whereas all odd digits are changed to the previous digit in the number series, then all the digits are rearranged in ascending order from left to right. Which of the following numbers the positions of two or more digits remain unchanged?

I. 3574826

II. 4857923

III. 5986432

A. Both I and III

B. Only II

C. Both I and II

D. Only I

E. None of these

Sol:

From I: 3574826 → 2465937 → 2345679 (no digit remains unchanged)

From II: 4857923 → 5946832 → 2345689 (no digit remains unchanged)

From III: 5986432 → 4897523 → 2345789 (no digit remains unchanged)

Hence, option E is the correct choice.