Select the term that will come next in the following series.
OBE, PDH, QFK, RHN, ?

OBE, PDH, QFK, RHN, ?

Relation between the first letter of each terms

$$O \ \underrightarrow{+1}  \ P \ \underrightarrow{+1}  \ Q \ \underrightarrow{+1}  \ R \ \underrightarrow{+1}  \ S$$

Relation between the second letter of each terms

$$B \ \underrightarrow{+2} \ D \ \underrightarrow{+2} \ F \ \underrightarrow{+2} \ H \ \underrightarrow{+2} \ J$$

Relation between the third letter of each terms

$$E \ \underrightarrow{+3} \ H \ \underrightarrow{+3} \ K \ \underrightarrow{+2} \ N \ \underrightarrow{+2} \ Q$$

So next term will be SJQ