$\text{A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}$
After reversing 2nd half ( after 13th symbol):
$\text{ A B C D E F G H I J K L M Z Y X W V U T S R Q P O N}$
now sixth to the right of the 18th letter from the left:
18th letter from the left is $V$,so 6th alphabet from the right of $V$ will be $P$
Option $(B)$ is correct.