Final answer:
According to Piaget, Janelle does not understand the concept of conservation.
Step-by-step explanation:
According to Piaget, Janelle's understanding of the two clay balls would fall under option 2) She does not understand the concept of conservation. Piaget's theory of cognitive development suggests that children in the preoperational stage, typically between the ages of 2 and 7, have not yet developed an understanding of conservation. Conservation is the idea that even if the appearance of something changes, its size, volume, or number remains the same. In the preoperational stage, children tend to focus on the way something looks rather than its underlying properties. Therefore, Janelle would not have a fully developed understanding of conservation at this stage of cognitive development.