In Choose odd Letter Group type questions, usually five groups of letters are given. Four of them are similar to each other in some manner while one is different and this is to be chosen by the candidate as the answer.
BDGK, JLOS, NPSW, MORU, HJMQ
Clearly, the answer is (d).
In all groups, there is gap of 1 letter between first and second letters, 2 letters between second and third letters, and 3 letters between third and fourth letters.