Answer:
Clock input( or Timer Oscillator) in used to change the state of the output.
Step-by-step explanation:
Flip-flop is an device that is the state changes with the rising or falling of the clock. It has a control signal (clock) input that stores the input state and outputs the state only in response to the clock signal.
The output changes with the change in the input in synchronization with the clock.
Whenever the input of the clock changed, it will result in change in the output.