6.2 For each of the following functions, find all of the prime implicants, using the Quine- McCluskey method. (a) la, b, c, d) = E m(1, 5, 7, 9, 11, 12, 14, 15) O (b) Aa, b, c, d) E m(0, 1, 3, 5, 6, 7, 8, 10, 14, 15)