The correct answer is: A. Alpha = max
Alpha-beta pruning is a search algorithm that is used to find the best move in a game tree. It works by iteratively searching the tree, starting at the root node and expanding each node only as far as necessary. The algorithm maintains two values, alpha and beta, which are used to bound the search space. Alpha is initialized to a value that is greater than or equal to the best value found so far, and beta is initialized to a value that is less than or equal to the best value found so far.
The algorithm then expands the root node and evaluates the value of the child nodes. If the value of a child node is greater than or equal to alpha, then alpha is updated to the value of the child node and the algorithm prunes the rest of the subtree rooted at that node. Similarly, if the value of a child node is less than or equal to beta, then beta is updated to the value of the child node and the algorithm prunes the rest of the subtree rooted at that node.
The algorithm continues to expand nodes and update alpha and beta until a leaf node is reached. The value of the leaf node is then returned as the best move.
In the case of the question, alpha is assigned to the maximum value of the children of the current node, while beta is assigned to the minimum value of the children of the current node. This is because the algorithm is trying to find the best move, which is the move that results in the maximum value for the player.
The other options are incorrect because they do not correctly represent the way that alpha and beta are assigned in alpha-beta pruning.