Given series $:ZA,RS,DE,JK,PR,LM,YZ,NO$
We know that $Z = 26,A = 1,R = 18,S = 19,D = 4,E = 5,J = 10 ,K = 11,P = 16, R = 18,L = 12, M = 13,Y = 25, Z = 26,N = 14 , O = 15. $
The difference between each pair is $1,$ but $PR$ doesn’t follow.
So, the correct answer is $(D).$