The Structure of the Sliding Clamp Is ____ in Bacteria

The structure of the sliding clamp is ____ in bacteria, archaea and eukaryotes, which likely indicates that ____. ​

A) largely variable; the function of the sliding clamp is different in these organisms ​
B) largely variable; the function of the sliding clamp is similar in bacteria and archaea but different in eukaryotes
C) highly conserved; the sliding clamp is involved in different processes depending on the organism
D) highly conserved; the function of the sliding clamp is similar in these organisms
E) largely variable; the sliding clamp is not essential for DNA replication