4. (4 marks) A sequential circuit has two JK flip-flops A and B, and one inputs x, as shown in the figure below. clk a) 1 mark) Tabulate the state table of the circuit. b) (1 mark) Draw the corresponding state diagram. c(1 mark) Assuming that the machine starts in state 00 and x is always 1, draw a timing diagram for clk, x, A and B for 10 clock pulses. d) (1 mark) Explain clearly the function that the circuit performs