a$)$ Explain the difference between 'rationality' and 'intelligence' in the context of human cognition, and provide examples to illustrate each concept?

b$)$ How do virtual agents in simulation and training; and assistive technologies for people with disabilities embody the approach of "modeling systems that act like humans," and what are the benefits of employing such systems in their respective domains?

c$)$ Explain how Depth First Search algorithm works. Support your answer with an algorithm that indicate steps