The most appropriate statement is (c) they may attract or repel depending on the type of charges they carry.
Explanation: If the objects have opposite charges, they will attract each other. If they have the same charges, they will repel each other.
Why other options are incorrect:
(a) they may attract: This is not a complete answer because it only covers one possibility.
(b) they may repel: This is not a complete answer because it only covers one possibility.
(d) there will be no effect: This is incorrect because charges always interact with each other, either attracting or repelling.