Final answer:
Option 1: "Yes, the infant will feel a brief pinch, but it will be over quickly."
Step-by-step explanation:
The best response for the nurse to make when asked by the parents if their infant will feel pain during a heel stick is Option 1: "Yes, the infant will feel a brief pinch, but it will be over quickly." This response provides an honest and accurate explanation that acknowledges the potential for pain but reassures the parents that it will be brief. It is important for the nurse to be transparent with the parents and manage their expectations.