If you have already removed a character (in char variable ch) from the input stream, you can apply a member function of cin to the variable ch to return it to the input stream. Which of these does this task? Select one: a. cin.peek(ch); b. cin.putback(ch); c. cin.put(ch); d. cin.get(ch); A friend function has access only to the private members and member functions of the class (and all objects of that class) of which it is a friend. Select one: True False A constructor (2 correct) Select one or more: a. usually initializes all, or most, member variables b. can only be used to initialize c. must initialize all member variables d. can do anything any other method can do