Explanation : The complement of the language L = {anbm|n ≥ 4, m ≤ 3} is L` = {anbm|n < 4} U {anbm|m > 3}: L` = Universal set - L. L` = Universal set - {anbm|n ≥ 4, m ≤ 3} = (λ + a + aa + aaa)b* + a*bbbbb* + (a + b)* ba(a + b)* Option (D) is giving freedom on constraints on number of a's and number of b's. So, option (D) is correct.