In the following alphanumeric series, what letter comes next? k N P S U

The given series is

K N P S U

And we have to find what will be the next alphabet.

First we have to understand the pattern.

The difference between N and K is of 2 alphabets, and between P and N is of 1 alphabet, between S and P is of 2 alphabets, and between U and S is of 1 alphabet.

So the pattern of the differences between the alphabets are

2 1 2 1

So the next is of 2 alphabets

And the alphabet that comes after two alphabet from U is X.

So the next alphabet is X.