ADGJ, YVSP, KNQT, ?
Each group forms an arithmetic sequence of letters with step \(3\).
The directions alternate: \(+3\) (ADGJ), then \(-3\) (YVSP), then \(+3\) (KNQT).
So the next must be \(-3\): \[ O\,(\!-\!3\!)\,L\,(\!-\!3\!)\,I\,(\!-\!3\!)\,F. \] \[ \boxed{\text{OLIF}} \]