WHAT IS THE TONE OF THE PASSAGE

3. - File thứ 1: De va dap an thi thu lan 2, Anh
Tiếng Anh File thứ 1: De va dap an thi thu lan 2, Anh
3. What is the tone of the passage? A. A personal account of helicopter development. B. A comparison of helicopters and fixed wing aircraft. C. An impartial overview of the development of helicopters. D. A biased representation of the development of helicopter flight.