Extension, Denaturation, Annealing

You are correct that all three steps are important for a PCR. In the extension step, the temperature is raised to around 72°C to allow the DNA polymerase to bind to single-stranded DNA to synthesize the new DNA strand by adding nucleotides to the primer. Which step allows the formation of single-stranded DNA? This needs to happen first before proceeding with the next two steps. Please think about this question and try again.