I created zoo class and animal class for this test(OOP applied), setting up interactions between zoo keeper and animals inside the zoo, and finally design a simple UI for displaying the current zoo status and and inputting commands. Few days after the completion, I received the feedback mentioning that my approach is not OOP enough(?); this is so confusing since they did not provide furthur information about it. They should probably be more specific about their requirements since it seems that my solution fulfills all the requirements stated in their description doc.