Select the alphanumeric group from the given options that will replace the question mark (?) in the following series.
S77, U52, X32, ? , J7, U2
1
B17
2
C18
3
C17
4
C20
Select the alphanumeric group from the given options that will replace the question mark (?) in the following series.
S77, U52, X32, ? , J7, U2