Question 20 6 pts An algorithm A that uses backtracking traverses a search tree from the root down. At each node, A checks whether a solution can be completed down the node. If it cannot, the associated sub-tree is O replaced O marked for revisiting O pruned O rotated Previous Next > Question 19 6 pt With the algorithmic technique, our programs systematically look over all possible candidate solutions to find one that meets the problem requirements. O randomization O combinatorial search dynamic programming brute-force