Step-by-step explanation:
It is known that like charges repel each other whereas opposite charges attract each other.
Since it is shown in the diagram that balloon A and B are moving towards each other. This means both of then are oppositely charged, that is why, they are attracted towards each other.
Whereas balloon C and B are moving in the opposite directions. This means both of them are having same charge, that is why, they are repelling each other.
Thus, we can conclude that balloon A is positively charged, and balloon C is negatively charged. If balloon A approaches balloon C, there’ll be a force of attraction between them.