86000 Compute the smallest natural number congruent to (16 5 207 13 11 954 + 7) (mod 4). Hint: think before trying brute force. You don't need a calculator. O (a) 3 O (b) 2 O (c) 0 (d) 1 Let's define A = {1,2,4}. B = {3, 4, 8, 10}. C = {1, 4, 8, 9}. What is (B) U (AUC)? O (a) {1, 2, 3, 8, 9} O (b) {1,2,4} O (c) {4, 1, 8, 9} (d) {8, 9, 4, 2, 1}