Given the following statements, what is the output of each code segment below? (Assume #include has been coded at the top of the program): string heading = Exam Preparation Exercises; strng str; a. cout << heading.length(); b. cout << heading.substr(6,10); c. cout << heading.find(Ex); d. str = heading.substr(2, 24); cout << str.find(Ex); e. str = heading.substr(heading.find(Ex) + 2, 24); cout << str.find (Ex);