Final answer:
Heterogeneity is the key characteristic in IoT that represents the diversity of hardware platforms, operating systems, and networks of the IoT devices.
Step-by-step explanation:
The answer to the question regarding a key characteristic in the Internet of Things (IoT) where devices have different hardware platforms and networks is B. Heterogeneity.
This term describes the diversity of devices in terms of their hardware capabilities, operating systems, and the networks they connect to within the IoT ecosystem. This heterogeneity requires that IoT platforms are able to support a wide range of device types and communications protocols.
In IoT, heterogeneity is one of the key characteristics. This refers to the fact that devices in the IoT ecosystem have different hardware platforms and networks.
For example, in a smart home, you may have devices like smart bulbs, a smart thermostat, and a smart security system. Each of these devices may have different hardware specifications and connect to the network in different ways.
This diversity in hardware platforms and networks can pose challenges in terms of interoperability and compatibility between devices in the IoT system.