The correct answer is During replication, DNA is copied.
DNA replication is a molecular process by which DNA makes its own copy in a cell during cell division. The replication process begins with unzipping of DNA double helix in presence of the enzyme helicase. This enzyme breaks the hydrogen bonds as a result DNA double helix separated into the two single strands of DNA. The two separated strands acts as templates for the synthesis of the new strands of DNA. Thus, one DNA results into two DNA, this is called replication.
