EcoRI, a significant tool in rDNA technology is -

Enzyme

The correct answer is Option (3) - Enzyme

Restriction enzymes are named after the bacterial species from which they are originally isolated, and the Roman numeral is used to distinguish different enzymes isolated from the same species.

The convention for naming these enzymes is the first letter of the name comes from the genus and the second two letters come from the species of the prokaryotic cell from which they were isolated. For example, EcoRI is a type of restriction enzyme isolated from Escherichia coli (E. coli), and the Roman numeral I indicates that it was the first enzyme of this type to be discovered from this bacterial strain.