Analysis of "MOTHER" coded as "OMHTRE": Letter positions are rearranged as follows: - "M" (1st) moves to 2nd position. - "O" (2nd) moves to 1st position. - "T" (3rd) and "H" (4th) are swapped. - "E" (5th) and "R" (6th) remain in their original positions.
Applying the same pattern to "FATHER": - "F" (1st) moves to 2nd position. - "A" (2nd) moves to 1st position. - "T" (3rd) and "H" (4th) are swapped. - "E" (5th) and "R" (6th) remain in their original positions. Therefore, "FATHER" is coded as "AFHTRE". Answer: \(\boxed{D}\)