The option that he should implement would be a switchboard interface design. These design structures for graphic user interfaces use a single main page, large icons/buttons, a fixed navigation menu, and all the necessary functionality right in front of the user. This design is made with simplicity in mind in order to make it as easy as possible for a new user to pick up and efficiently and intuitively navigate the user interface. Therefore, since Calvin needs a simple yet professional design, this would be the best implementation.
