In the following question, select the related letter pair from the given alternatives.
BP: BO :: ?

Correct option is D

Given: BP: BO :: ?
The first letters of the pair are ‘ B’ and B. Here, the first letter remains the same.
The second letters of the pair are P and O. The change here is that O is one letter before P in the alphabet.
(a) OG : KB
The first letter O does not remain the same as K, so this option does not match.
(b) NB : JX
The first letter N does not remain the same as J, so this option does not match.
(c) EZ : BV
The first letter E does not remain the same as B, so this option does not match.
(d) LY : LX
The first letter L remains the same, and the second letter changes from Y to X (moving one letter back).
Thus, correct option is (d).