Select the option that is related to the third term in the same way as the second term is related to the first term.
ACEG : BDFH :: CEGI : ?

ACEG :Each letter has +2 alphabet in next letter

A + 2 = C ;  

C + 2 = E ;  

E + 2 = G =  ACEG 

for finding Next series first letter A + 1 = B ;

B + 2 = D ;  

D + 2 = F ;  

F + 2 = H  = BDFH 

for finding Next series take first letter B + 1 = C ;

C + 2 = E ;  

E + 2 = G ; 

E + 2 = I = CEGI

Similarly, 

For finding Next series take first letter C + 1 = D ;

D + 2 = F ; 

F + 2 = H  ;  

H + 2 = J ;

Hence DFHJ is correct Option.