Problems 06-10 are based upon the following class declaration appearing in unknown.h All member functions will be defined in the file unknown.cpp class Unknown private: int a; public: Unknown ); void SetA (int aa); // Sets a equal to aa int GetA ) const; // Returns value of a // Initializes a to 0 06. VWhich of the following is a valid implementation for SetA)? A) void SetA() const B) void Unknown::SetA() const C) void Unknown:: SetA() aa = a; a aa; D) void Unknown:: SetA) const E) None of the answers provided a = aa; 07. Which of the following is a valid function heading for the function Unknown? A) void Unknown); B) void Unknown::Unknown() C) int Unknown::Unknown() D) Unknown::Unknown) E) None of the answers provided 08. VWhich of the following is a valid function heading for the function GetA? A) int Unknown::GetA() B) void GetAO C) void Unknown::GetA() D) int Unknown::GetA() const E) None of the answers provided 09. Suppose that a client program has a variable X of type Unknown. Which of the following statements correctly outputs the current value of the private member a of the variable X? D) cout