What is the number of measuring components that can be tied to a device determined by?
A. the number of measuring components, such as channels or registers, required by the usage subscription type
B. the number of valid head-end systems from which measurement data can be received for the device type
C. the number of measuring components, such as channels or registers, required by the device configuration type
D. the number of measuring components, such as channels or registers, required by the installation event type