The correct option is D RTNP
Here in the first term on the LHS the letters in positions 3, 4, 1 and 2 are alternate letter The second term on the LHS also follows the same pattern Further, the second letter of the first term and the third letter of the second term also alternate letters
It is observed that the first term on the RHS also follows the above pattern
Only the letter in option 4 follow this pattern Further the second letter L of the first the term on the RHS and the third letter of option (4) i.e., 'N' are alternate letter Hence the answer is R T N P