"From a function with 4 inputs (a, b, c, d) and 2 outputs (x, y) that have specific relationships only in 4 cases (the rest are Don't Care), as follows: (a, b, c, d, x, y)= ((0, 0, 1, 1, 1, 0), (0, 1, 1, 0, 0, 1), (1, 1, 0, 0,0, 1), (1, 0, 0, 1, 1, 0)), create two circuits as follows: a. Left circuit: X = AD + CD, Y = AB + BC b. Right circuit: X = ABCD + ABCD, Y = ABCD + ABCD Please answer the following questions: 4.1 In the case of a Stuck at O fault occurring at input A of gate AD in the left circuit, find the input (codeword) that still maintains a Fault Secure state. Is the circuit in this case Totally Self Checking or Strongly Fault Secure? 4.2 In the case of a Stuck at 1 fault occurring at input C of gate ABCD in the right circuit, find the input (codeword) that can be used for Self Testing. Is the circuit in this case Totally Self Checking or Strongly Fault Secure?" A-X D D A B 8-3-0 B AD CD AB BC 3-a-1 ABUD AB CD AB CD AB CD AB CD