What are the disadvantages of balling/kites and parachutes?

The option suggesting that balling/kites and parachutes may risk flooding buildings is accurate because these devices are intended to help with the flow of sewage and wastewater within pipeline systems. If these devices malfunction or become lodged in a way that disrupts the flow, they can lead to backups or blockages. Such blockages can cause wastewater to overflow, ultimately resulting in flooding in connected buildings and areas. This risk highlights the importance of proper monitoring and maintenance of these devices to ensure they function effectively and do not compromise the system's integrity.

In consulting the other options, while cost factors, limitations on pipe size, and increased cleaning needs might be considerations with certain systems, they do not universally apply to all scenarios involving balling/kites and parachutes. Flooding, however, remains a significant and direct consequence of their potential operational failures, making it a primary concern in their use.