Final answer:
The correct answer is C) depolarization. When the hair-cell cilia bend toward the tallest stereocilia, the hair cells become depolarized, leading to the generation of nerve impulses.
Step-by-step explanation:
The movement of hair-cell cilia in a direction toward the tallest cilia results in depolarization. The stereocilia on hair cells in the organ of Corti are mechanoreceptors connected by protein fibers. These tethers open ion channels within the hair cell membrane when the stereocilia bend towards the tallest member of the array, causing the cell to depolarize. This depolarization triggers a nerve impulse, which travels down the afferent nerve fibers attached to the hair cells. Therefore, the correct answer to the question is C) depolarization.