Which statement about assessing model performance using the Model Comparison tool is true?

The statement about assessing model performance using the Model Comparison tool that holds true is that unless a profit matrix is defined, the tool selects the model with the smallest validation misclassification rate by default. This is significant as it indicates the tool's inherent mechanism to prioritize model evaluation based on its predictive accuracy.

When a profit matrix is not established, the focus shifts towards minimizing the misclassification rate, which is a critical factor in model performance. Misclassification rate measures how often the model incorrectly predicts the outcome, and choosing the model with the lowest rate indicates an emphasis on improving prediction reliability.

The other options touch on various functionalities of the Model Comparison tool but do not accurately reflect the default behavior it exhibits in the absence of a profit matrix. By prioritizing the misclassification rate, the tool effectively streamlines the model selection process, making it easier for practitioners to choose a model that performs well based on a clear and straightforward criterion.