Answer: The correct option is C. Pre-operational stage.
Explanation: According to Piaget, the Pre-operational stage is a stage in which a child's cognitive development has not been fully established. This period will usually begin at toddlerhood, around 18-24 months and last through to the age of 7.
At this stage, a child has not yet developed the notion of quantity, therefore, the ability to solve problems like the example given above, has also not been developed due to the fact that logical thinking has not been established.
In the scenario given in the question above, James is not able solve this problem because his cognitive abilities and logical thinking is still developing.