The civic authority is getting benefited due to biocomposting -> as it reduces the amount of waste they have to dispose of. This is because organic waste is being converted into compost -> which is then used by farmers, thus reducing the quantity of waste that needs to be disposed of. The correct answer is:
They have to dispose increased quantity of waste.
They don't have to dispose any waste.
Because civic authority has no role in waste management
They have to dispose reduced quantity of waste
The correct option is 4.