__ is an enzyme in molecular biology responsible for keeping the unzipped DNA strand from super coiling. a. Helicase b. primase c. ligase d. topoisomerase

The correct answer is d. topoisomerase.<br /><br />Topoisomerase is an enzyme that helps to relieve the torsional strain that builds up in the DNA molecule during processes such as replication and transcription. It does this by cutting, unwinding, and rejoining the DNA strands, allowing the DNA to be unzipped without supercoiling.