In a decision tree, the independent variable found at each branch of the tree is known as a _________.

• A. Node
• B. Split
• C. Branch
• D. Test

Answer: (A)

In a decision tree, the feature you use to split the data at any point is stored where the decision is made—the node. Each internal node represents a test on a specific attribute, and the outcome of that test determines which branch you follow next. The edges (branches) simply represent the results of that test, not the variable itself, and a split is the action of dividing data based on that test, while a leaf gives the prediction. So the element that holds the independent variable used for splitting is the node, making it the best term to describe where the decision on that variable is defined.