Can someone please help me

1)consider the following code snippet: #ifndef book_h#define book_hconst double max_cost = 1000.0; class book{public: book(); book(double new_cost); void set_cost(double new_cost); double get_cost() const; private: double cost; }; double calculate_terms(book bk); #endifwhich of the following is correct? a)the header file is correct as given.b)the definition of max_cost should be removed since header files should not contain constants.c)the definition of book should be removed since header files should not contain class definitions.d)the body of the calculate_terms function should be added to the header file.

Need asap write a short paper describing the history and differences between six sigma, waterfall, agile, and scrum models. understanding these models can give you a good idea of how diverse and interesting it development projects can be. describe what the rationale for them is and describe their key features. describe the history behind their development. at least 400 words

Design a class tictactoe that: holds the following information about the game: two-dimensional array (3 by 3), and winner. add additional variables as needed. includes the functions to perform the various operations on objects. for example, function to print the board, getting the move, checking if move is valid, determining if there is a winner after each move. add additional operations as needed. includes constructor(s). write the functions of the class, and write a program that uses the class. the program should declare an object of type tictactoe. the program will create the board and store it in the array. the program will allow two players to play the tic-tac-toe game. after every valid move update the array, check if there is a winner. if there is no winner and no tie, then print the board again to continue.