Select the letter-cluster that can replace the question mark (?) in the following series.

PERSONA, ANPERSO, ANOSPER, ?

ANOSREP

The pattern in the given series involves rearranging the letters in each term. Let's analyze the transformation:

1) PERSONA

2) ANPERSO (Shift the first letter to the end)

3) ANOSPER (Shift the first letter to the end)

4) ANOSREP (Shift the first letter to the end)

So, the correct option to replace the question mark (?) is ANOSREP.