What will come in place of blank space (_) in the following series.
_ o p _ m o _ n _ _ p n m o p _

Given: _ o p _ m o _ n _ _ p n m o p _ 

Now, we check each options.

Option (a): m n o m p n

m o p n / m o o n / m p p n / m o p n 

Option (b): m p n m o p

m o p p / m o n n / m o p n / m o p p 

Option (c): m n p o m n

m o p n / m o p n / o m p n / m o p n 

Option (d): m n p m o n

m o p n / m o p n / m o p n / m o p n 

The pattern is follow: m o p n

Thus, correct option is (d).