A. If the inputs to control systems are gradually changing functions of time, then a/an _____ will be a good test signal.B. If a system is subjected to sudden disturbances, a/an _____ function will be a good test signal.C. For a system subjected to shock inputs a/an _____function will be a good test signal

• A. impulse, ramp, step
• B. ramp, step, impulse
• C. impulse, step, ramp
• D. ramp, impulse, step