A company has a Virtual Machine created in their subscription. An application is installed on the Virtual Machine. You need to ensure that traffic can flow into the Virtual Machine on port 8080. Which of the following must you modify to make this work?

Answer options:

A.Network Interface Card
B.Network Security Group
C.Route Tables
D.Route Filters

Answer – B 
You have to modify the Network Security Group. You have to add an Inbound Security Rule. An example is shown below. 

So first add the Inbound Security rule.
Add the destination port range as 8080.
Ensure that the Action is Allow.
Since the right implementation is via Network Security Groups, all other options are incorrect. 
For more information on network security groups, please visit the below URL- 

https://docs.microsoft.com/en-us/azure/virtual-network/security-overview