Select the letter-cluster from among the given options that can replace the question mark (?) in the following series: GBDF, GHMR, GNVD, GTEP, ?AGZMBBGZNCCGZNBDGYNBAnswer: C. GZNB Read Explanation: Let's examine each position in the letter cluster separately.Series:GBDFGHMRGNVDGTEP?1st letterG, G, G, G → constant → G2nd letterB (2), H (8), N (14), T (20)Each increases by +6:20 + 6 = 26 → Z3rd letterD (4), M (13), V (22), E (5)Each increases by +9 (wrapping around after Z):5 + 9 = 14 → N4th letterF (6), R (18), D (4), P (16)Each increases by +12 (wrapping around):16 + 12 = 28 → 2 → BSo the next letter-cluster is:GZNB Read more in App