As part of an IoT solution, you have to deploy image recognition logic to certain field devices, in order to complete computation-intensive tasks locally. The devices are already registered in the IoT Hub as edge devices. Your task is to go on with their configuration and deploy the runtime logic. You have to deploy 2 interdependent custom modules (TempSensor, Filter) to your device. To define the flow of data between them, you add the following configuration to your deployment manifest: 
<pre class="brush:java;">"$edgeAgent": {
"properties.desired": {
"schemaVersion": "1.1",
"routes": {
"sensorToFilter": {
 "route": 
"FROM /messages/modules/TempSensor/outputs/temperatureOutput 
 INTO BrokeredEndpoint(\"/modules/Filter/inputs/inp1\")",
 "priority": 0,
 },
"filterToIoTHub": {
 "route": 
 "FROM /messages/modules/Filter/outputs/output1
INTO $upstream",
 "priority": 1,
 "timeToLiveSecs": 1800
}
},
"storeAndForwardConfiguration": {
"timeToLiveSecs": 100
 }
 }
}
</pre>
Does the code do its job as expected?

Answer options:

A.No. It must be part of the $edgeHub config
B.No. The TempSensor’s source should be set to $downstream
C.No. The timeToLiveSecs from sensorToFilter route is missing
D.Yes, it is correct.

Correct Answer: A
Option A is CORRECT because actually, configuration of the routes between the edge modules must be described under the $edgeHub tag since it is the edgeHub that is responsible for the orchestration of the message flows between the modules.
Option B is incorrect because the sensorToFilter route connects the TempSensor to the Filter module, therefore its source setting is correct. $downstream is not a valid source setting.
Option C is incorrect because the timeToLiveSecs parameter of the routes inherits its value from the storeAndForwardConfiguration of the edgeHub if it is not explicitly set, i.e. it is not required.
Option D is incorrect because the configuration of the routes between the edge modules must be described under the $edgeHub tag, rather than the $edgeAgent.
References: 

https://docs.microsoft.com/en-us/azure/iot-edge/module-edgeagent-edgehub?view=iotedge-2018-06
https://docs.microsoft.com/en-us/azure/iot-edge/module-composition?view=iotedge-2018-06#deployment-manifest-example
https://docs.microsoft.com/en-us/azure/iot-edge/module-composition?view=iotedge-2018-06#declare-routes