Final answer:
To leverage the 100 Mbps throughput for an accounting business with nine employees, one needs to purchase a cable-based wireless router with channel bonding capability.
Step-by-step explanation:
To take full advantage of the 100 Mbps throughput offered by the cable company for an accounting business with nine employees, the necessary purchase is A) a cable-based wireless router that supports channel bonding. Channel bonding is a technology used by cable internet providers to combine multiple channels for increased bandwidth. A cable-based wireless router will allow the business to distribute the internet connection wirelessly to the employees' devices, ensuring that they can all benefit from the high-speed connection provided by the cable company.
Channel bonding is related to internet delivery and not to other services such as cable TV subscriptions or satellite dishes, thus making choices C) and D) irrelevant for this purpose. Network cables (B) might be a requirement for connecting devices that don't have wireless capabilities or for providing wired connections for more stability and speed.