Final answer:
The parent's statement indicating an understanding of the teaching is that they should not mix valproic acid (Depakene) syrup with carbonated beverages.
Step-by-step explanation:
The correct statement made by the parent indicating an understanding of the teaching is option d. "I should not mix this with carbonated beverages." This statement shows that the parent understands that valproic acid (Depakene) syrup should not be taken with carbonated beverages as it can affect the absorption and effectiveness of the medication. It is important to take medications as instructed by the healthcare provider to ensure their optimal effect.