Annealing, Denaturation, Extension

You are correct that the annealing step is an important one in the PCR. In the annealing step, the temperature is lowered to 50-65°C to allow primers to bind to the single-stranded DNA. 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 reconsider your response.