Where Do Restriction Enzymes Come From,and What Is Their Normal

Multiple Choice

Where do restriction enzymes come from,and what is their normal physiological function?

A) Phage produces them and they replicate viral DNA.
B) Phage produces them and they confer antibiotic resistance.
C) They are yeast DNA replication enzymes.
D) Bacteria produce them to protect against viral invasion.
E) They are bacterial DNA replication enzymes.