Final answer:
The system being interactive with its environment is required for a physical computing system. Other options are not necessary.
Step-by-step explanation:
The correct answer is D) The system is interactive with its environment. In a physical computing system, the ability to interact with the environment is essential. This can be achieved through sensors, actuators, and other components that allow the system to sense and respond to changes in its environment. For example, a smart home system that can detect motion and adjust the lighting accordingly is interactive with its environment.
A) The device looking nice for users is not a requirement for a physical computing system. It is more related to the design aspect and user experience.
B) The system being connected to the internet is not a requirement for a physical computing system either. While internet connectivity can enhance the functionality of a system, it is not a fundamental requirement.
C) The components being waterproof can be important for certain applications, such as outdoor systems or those exposed to water. However, it is not a requirement that applies to all physical computing systems.