Answer:
In order to satisfied the law of conservation of charge, If the rubber rod becomes negatively charged, then the fur becomes positively charged.
Step-by-step explanation:
This law states that charge is neither created nor destroyed, it can only be transferred from one system to another. In this case the rubber rod obtains electrons from the fur, in consequence the rod, which was originally neutral becomes negatively charged (the number of electrons on it increase), and the fur which was originally neutral becomes positively charged (the number of electrons on it decrease).