Final answer:
The nurse should mention Option 3: Use the cream sparingly and monitor for any signs of allergic reactions.
Step-by-step explanation:
The nurse should mention Option 3: Use the cream sparingly and monitor for any signs of allergic reactions. When applying an anesthetic cream to a toddler, it is important to use it sparingly to avoid an overdose and monitor for any signs of allergic reactions. Applying the cream generously or covering it tightly with a bandage can increase the risk of systemic absorption, which may lead to adverse effects.