Which of the following statements applies/apply when a pulse, travelling along an ideal spring, is reflected from a fixed point at the end of the spring? I. The amplitude of the reflected pulse is equal to the amplitude of the incident pulse. II. The length of the reflected pulse is equal to the length of the incident pulse. Ill. The speed of the reflected pulse is equal to the speed of the incident pulse. Select one: O a. I and II O b. I and Ill O c. Il and Ill O d. I, ll, and Ill