Select the option that represents the letters that, when placed from left to right in the blanks below, will complete the letter-series.
a_ m x _ q _ y c _ o _ ​

Given: a_ m x _ q _ y c _ o _
Option (a): prnbx

​a p m x / n q b y / c r o z

(Not follows a logical pattern)

Option (d): pbnrz
a p m x / b q n y /c r o z
Logic: +1, +1, +1 pattern follows after filling.
first letter of each term- abc
second letter of each term - pqr
third letter of each term - mno
fourth letter of each term - xyz
so, option d is the correct answer​​​