Four letter evenly spaced ladder groups – UGC NET Question

Each group here consists of four letters that are all equally spaced from each other in the alphabet. ADGJ has evenly increasing positions, and BEHK, CFIL and DGJM repeat the same internal spacing with their own starting letters. From one group to the next, every letter moves forward by one place, so the columns form simple increasing sequences. Moving each letter of DGJM forward by one produces EHKN, which is the only option that keeps the equal spacing and column wise step, making it the correct continuation.

Option A:
Option A is correct because EHKN follows directly after DGJM when each column is advanced by one letter. The distances between E, H, K and N match those inside the earlier groups exactly. It therefore extends both the vertical progressions and the internal even steps of the series.

Option B:
Option B, EHKM, uses the correct first three letters but changes the last letter so that the gap from K to M differs from the established spacing. This small alteration breaks the exact pattern that has been followed consistently. Because the internal distances are disturbed, EHKM cannot be the next term.

Option C:
Option C, FIKN, begins with F instead of E and alters multiple letters, which no longer come from a simple one step shift of DGJM. Its internal arrangement does not fit the regular ladder structure of the series. Hence FIKN is not acceptable as the correct answer.

Option D:
Option D, EGKM, mixes letters that do not align properly with the existing column sequences and ignore the equal spacing between positions. The changes in the inner parts of the group do not match the mechanical rule used earlier. Therefore EGKM does not continue the series correctly.