Answer: The correct answer is "Both B and C are positively charged".
Explanation:
Same charges repel each other. There is an electrostatic force of repulsion between the same charges.
Unlike charges attract each other. There is an electrostatic force of attraction between the opposite charges.
In the given problem, consider four objects: A, B, C, and D. If A is negatively charged and B and C attract A but repel each other.
In the given question, B and C repel each other. It means that both B and C have same charge. A is negatively charged. Then, B and C have positive charge. As B and C attract A. Both B and C are positively charged.
Therefore, the option (B) is correct.