Concept:The series follows a pattern of adding 7 to the position of each letter in the alphabet, wrapping around from Z to A.Explanation:Assign numbers to letters: G = 7, N = 14, U = 21, B = 2 (since 21 + 7 = 28, subtract 26 gives 2).Add 7 to each: 7 → 14 → 21 → 28 (2) → next: 2 + 7 = 9, which is I.Thus the next letter is I.
