Select the option that represents the letters that, when placed from left to right in the given blanks, will complete the letter series.
N O P _ Q N O _ I Q N _ P H Q _ O P G _

Correct option is B

N O P _ Q N O _ I Q N _ P H Q _ O P G _
Form the option (b)
N O P J Q/ N O P I Q/ N O P H Q /N O P G Q
In the given series J → I → H → G are decreasing and remaining letters are same.
Therefore, the correct option is (b).