Four light-emitting diodes(LED) are arranged at the conrnersof a diamond, When logic 1 is applied to an LED, it lights. Only one diodeis to be on at a time. The on state should move from diode to diodeeither clockwise or counterclockwise, depending on whether S ishigh or low, respectively. One complete revolution should becompleted in each two-secound interval. (a) What is the frequencyof the clock? (b) Draw a suitable logic circuit for the counter.(c) Construct the truth table and use Karnaugh maps todetermine the minimum SOP expressions for D1 through D4 in terms ofS, Q1, and Q2.