Answer:b)via radio signals
Explanation: Machine-to-machine technology is the technology that helps in sharing of the real time information of the device that have embedded sensor.They can work without the help of the manual factors.
The data is shared through the help of the radio signals in the devices like turbines vending machines etc for the tracking purpose and managing.
Thus the other options are incorrect because short distance is a disttance, cloud services are for the collection of services and databases contains the data. So, the correct option is option (b).
At the bottom right is the perfect place
