You are using IoT Central to manage your field devices. You want to connect your previously registered thermostat device to IoT Central. Here is the code your device uses for provisioning: 
<pre class="brush:java;">...
# PROVISION DEVICE
async def provision_device(provisioning_host, id_scope, registration_id, symmetric_key, model_id):
provisioning_device_client = 
ProvisioningDeviceClient.create_from_symmetric_key(
provisioning_host=provisioning_host,
registration_id=registration_id,
id_scope=id_scope,
symmetric_key=symmetric_key,
)
provisioning_device_client.provisioning_payload = {"&lt;......&gt;": &lt;......&gt;}
return await provisioning_device_client.register()
... </pre>
Which of the parameters used by the registration service to find the corresponding template for the device?

Answer options:

A.registration_id
B.id_scope
C.model_id
D.symmetric_key

Correct Answer: C
Option A is incorrect because the registration ID is required, but it is used to uniquely identify a device by the Device Provisioning Service.
Option B is incorrect because while the ID scope is required, it is used to identify the provisioning service the device will be registered by.
Option C is CORRECT because it is the device model that is used by the device provisioning service to associate the device with its corresponding device template. This is used to determine the capabilities the device has. Moodel_id of a device in the model description looks like this: "@id": "dtmi:com:example:Thermostat;1"
Option D is incorrect because the symmetric key is the key that will be used to create the shared access signature token to authenticate the device with DPS.
References: 

https://docs.microsoft.com/en-us/azure/iot-central/core/concepts-get-connected#associate-a-device-with-a-device-template
https://docs.microsoft.com/en-us/azure/iot-central/core/tutorial-connect-device?pivots=programming-language-python