(a) What is the relationship between classes and objects? [2 marks] (b) Why do we use classes to group together different data types? In your answer, you should list some of the advantages of classes. [4 marks] (c) You are asked to write a simple class for an object called Counter that has a single integer variable counterVar and, apart from constructors, a single public function addone with the signature: void addone that adds one to the counterVar variable. Write the C++declaration code for this class