2. a) Explain the process of generating an executable file from the source code files. 6 b) Explain what friend functions are used for. c) Define what the destructor of a class is, give an example of what it can be used for (no code is required) d) You are given the following code, specify whether the variables are allocated on static or dynamic memory: 2 2 2 int i{ }; int &r=i; double Array[5]; char *letter{nullptr}; int *number= new int(); vector data; 2 2 2