- AB, H, O, X
- BA, D, O, W
- CC, M, T, Y
- DA, H, O, X
Step-by-Step Solution
A letter is unchanged in an upright mirror when it has a VERTICAL line of symmetry. A, H, M, O, T, W, X and Y have one; B, C and D have only a horizontal line of symmetry. Every other group contains B, C or D.
Answer: D) A, H, O, X