The correct option is A OV
AD, CG, FK, JP are given terms. The first letter in each term A,C,F,J are respectively 1,3,6,10 letter of alphabetical sequence.
A=1; 1st letter of alphabetical sequence
C=1+2=3; 3rd letter of alphabetical sequence
F=1+2+3=6; 6th letter of alphabetical sequence
G=1+2+3+4=10; 10th letter of alphabetical sequence
The next term should begin with
1+2+3+4+5=15th
letter of alphabetical sequence. So, next term should begin with O.
Also in the series AD, CG, FK, JP, two letters in each term are separated by 2,3,4,5 letters in between them respectively. Hence, next term should be OV as there should be a gap of 6 alphabets between O and V.
Hence answer is OV.