Answer:
I. The class methods and instance methods of one class may call the public class methods of another class using dot notation and referencing the name of the other class.
Explanation:
Private methods are being accessed from only within the class or scope specified. No other means of accessibility is possible, and even through inheritance. And instance methods can never call without using dot notation, any of the class method of the same class. Hence second and third options are not correct. And the class method and the instance methods of one class may call the public class methods of another class using the dot notation and referencing the name of the other class. Hence, the correct option is the first one.
By looking at your code, it seems like you're trying to let the user enter positive numbers until the user enters a negative number. To achieve this, you need to indent int(input("Enter a number, negative to stop")) inside the loop.
The second answer choice is correct.
Im not completely sure, but i believe the answer is b. Different switches can be used at different times which have different outputs. You could switch cases in one program and use a different one in another and get different outputs.
