Refer to the Diagram Below of the Cochlea

Refer to the diagram below of the cochlea. Which of the following statements about the diagram is true?

A) If structure 1 vibrates slowly, the displacement pressure is dissipated by outward bulging of structure 4.
B) If structure 1 vibrates rapidly, structure 5 flexes.
C) The more rapid the vibrations of structure 1, the greater the amplitude of flexion of structure 5 at position X.
D) High-pitch sound waves are detected at position Z.
E) The organ of Corti is part of structure 5.