The correct answer to the question “Which of these business processes can be automated with RPA” is an option (D); All of the above. As all the three options paying accounts, the Human Resource, and the Mailroom could be transformed through the implementation of RPA, which would initiate better efficiency and more productivity.
If you wish to get trained in automation tools, I would highly suggest you check out the RPA certification course, from Intellipaat. As they offer industry-best training of 24hrs with 48hrs for exercises and projects to help you acquire the practical experience. Also, take a look at our YouTube video on Selenium Automation vs Robotic Process Automation to have a better understanding of both these tools.