Find all prime implicants and all minimum sum-of-products expressions for each of the following functions. Underline the essential prime implicants in your answer and tell which minterm makes each one essential.1.f(A, B, C, D) = Σ m(4, 11, 12, 13, 14) + Σ d(5, 6, 7, 8, 9, 10)2.f(A, B, C, D) = Σ m(1, 2, 4, 13, 14) + Σ d(5, 6, 7, 8, 9, 10)3.f(A, B, C, D) = Σ m(4) + Σ d(5, 6, 7, 8, 9, 10, 11, 12, 13, 14)4.f(A, B, C, D) = Σ m(4, 15) + Σ d(0, 1, 2, 5, 6, 7, 8, 9, 10)