In a certain code, MOTHER is written as ONHURF. How will ANSWER be written in that code?

Answer: Option D

Divide the word into three groups of two letters each and write the letters of each group in the reverse order. In the group of letters so obtained, the second, fourth and sixth letters are each moved one step forward to get the code. Thus, we have : AN SW ER => NA WS RE => NBWTRF.