in. Which of the following loops is guaranteed to execute at least once? (a) counter-controlled while loop (b) for loop (c) do...while loop (d) sentinel-controlled while loop Qn2. Consider the following statement: int alpha [25][19]; Which of the following statements about alpha is true? (a) Rows of alpha are numbered O...24 and columns are numbered 0.3. (b) Rows of alpha are numbered O...24 and columns are numbered 1...10. (C) Rows ofalpha are numbered 1...24 and columns are numbered 0...9. (Cl) Rows ofalpha are numbered l...25 and columns are numbered 1...10. Qn3. Suppose the following letter grade class has been defined globally in a program: class Grade { private: char grade; public: Grade(char in_grade); void print(); }; Grade::Grade(char in_grade){ grade=in_grade; } void Grade::print(){ cout