To identify the set with the stronger interaction between two sets of electrically charged objects, the most relevant question the student can ask is:
Are the objects both positively charged or both negatively charged?
This is because the strength of the interaction depends on the nature of the charges involved. Objects with opposite charges (one +1 Coulomb and one -1 Coulomb) will attract each other, leading to a stronger interaction, while objects with the same charge will repel each other, resulting in a weaker interaction. The other questions, while relevant in different contexts, do not directly address the strength of the electric interaction.