In bacterial DNA replication, what is the primary function of DNA gyrase (a type II topoisomerase) ahead of the replication fork?

• A. It relieves positive supercoiling (torsional strain) by introducing negative supercoils using ATP-dependent strand passage.
• B. It seals nicks in the sugar-phosphate backbone by forming phosphodiester bonds between Okazaki fragments.
• C. It unwinds the DNA double helix at the replication fork by breaking hydrogen bonds between base pairs.
• D. It synthesizes short RNA primers required to initiate DNA synthesis on the lagging strand.

Answer: (A)