please solve all my doubts, will rate a good answer

please answer question a as well

answer provided

7. [4] Polymorphism: The box on the following page shows the definitions of a small C++ class hierarchy. (a) Draw a diagram showing the class hierarchy. (b) Determine what output the code will produce, describing carefully how you reach your conclusions. (c) Test a real implementation to verify your answer. (d) Identify which parameters are passed by value and which by reference. Taking account of the meaning of this, and what will be stored in the activation record when doiti and doit2 are called, explain the result. class Foo { public: void f() { std::cout