Where is DNA gyrase normally positioned as it changes positively supercoiled DNA into negatively supercoiled DNA in the replicating circular, bacterial chromosome?

A)It is permanently located at the origin.
B)It travels along the DNA behind the replication fork.
C)It travels along the DNA ahead of the replication fork.
D)It travels along the DNA at the replication fork as part of the replisome.
E)It is permanently located at the termination site of replication.