Which of the following can divide the frequency of a pulse train by 2?

A flip-flop is a bistable digital logic circuit that can store one bit of data. When configured as a toggle (T flip-flop) or when a D flip-flop's inverted output is fed back into its input, it will change its output state once for every full cycle of the input clock signal. Because it takes two clock pulses (one rising edge to toggle high, and the next rising edge to toggle low) to complete a single high-low output cycle, the output frequency is exactly half of the input frequency. Connecting multiple flip-flops in a chain allows for further frequency division. Logic gates like XOR and OR are purely combinational logic devices; they do not have memory and cannot independently perform frequency division. A multiplexer is a switch that selects one of several input signals and forwards it to a single output.