You have a basic digital circuit with a clock signal, Clk$,$ a data stream, D$,$ and an output, Q$,$ that operates as shown in the waveforms shown in the figure below. Define the propagation delay for this circuit.

The time the data must be held after the rising clock edge.

The time taken for the output to change from the input changing.

The time between two subsequent rising clock edges.

The time the data must be stable before the ris$/2$ clock edge.