A shift register can be used for Select one: A. Parallel to serial conversion to serial con B. Serial to parallel conversion C. All of them D. Digital delay line How many 3-to-8 decoder are needed to build a 6-to-64 decoder? Select one: Spark O A 8 OB.9 O C.6 D. 10 The number of half adder used to build 5-bits adder Select one: O A. 9 Spark OB. 5 OC.4 O D. 10