Skip one letter (+2 pattern). A(+2)=C, C(+2)=E, E(+2)=G, G(+2)=I.
Logic: Backward skip one letter (-2 pattern). Z(-2)=X, X(-2)=V, V(-2)=T, T(-2)=R.
Logic: Continuous alphabetical pairs. The next pair after GH is IJ.
Logic: The gap increases: B(+2)=D, D(+3)=G, G(+4)=K. The next jump is +5. K is 11th, so 11+5 = 16th letter, which is P.
Logic: First letters: A, B, C, D → E. Second letters (Reverse): Z, Y, X, W → V. The pair is EV.
Logic: Backward -2 pattern. Q is 17th, 17-2 = 15th letter, which is O.
Logic: Jump of 3 (+3 pattern). O is 15th, 15+3 = 18th letter, which is R.
Logic: Jump of 2 (+2 pattern). R is 18th, 18+2 = 20th letter, which is T.
Logic: Jump of 3 (+3 pattern). N is 14th, 14+3 = 17th letter, which is Q.
First letters jump by 4: A(+4)=E, E(+4)=I, I(+4)=M, M(+4)=Q. Second letters jump by 4: D(+4)=H, H(+4)=L, L(+4)=P, P(+4)=T. The answer is QT.