8. Given the following description of a class, answer the questions below. The Vehicle class has three member variables: a protected String type which identifies the type of vehicle, e.g. bicycle, automobile, truck, etc.; a protected int wheels, which specifies how many wheels the vehicle has; and a protected boolean engine which indicates whether the vehicle has an engine or not. a) Explain what the purpose of the keyword protected is. b) List some methods that the class Vehicle should have to be a useful class.