To identify the set with the stronger interaction between the electrically charged objects, the student should ask:
"Are the objects both positively charged or both negatively charged?"
This question relates to the nature of the charges involved in the interactions.
According to Coulomb's law, the strength of the interaction between two charged objects depends on both the magnitudes of the charges and the nature of the charges (whether they are like charges or opposite charges). If both objects in a set have the same charge (either both +1 or both -1 Coulomb), they will repel each other. If one object has a charge of +1 Coulomb and the other has -1 Coulomb, they will attract each other.
The other questions, while they provide context (such as distance, size, and mass), do not directly address the nature of the interactions in terms of charge types, which is crucial for determining the interaction strength.