91205
Hope you're still following this!! I had a better explanation to your answer, but then my computer crashed. So, I'll just put in my ten cents and say the answer is (D). It is known as flapping to equality, but the term is mis-leading as the blades do not actually flap, they "move down" on the advancing side through a reduction in pitch angle, and "move up" on retreating side through an increase. This serves to restore changes in angle of attack due to an airflow over the disc during level flight.