Which statement best describes testing data in machine learning?

• A. Testing data is used to determine how well the model is performing.
• B. Testing data includes answers.
• C. Testing data does not include the model's answers.
• D. Testing data is the same as training data.

Answer: (C)

Testing data is used to measure how well the model generalizes to new, unseen data. After training, you run the model on the test inputs and compare the predictions to the true outcomes to assess performance. The test data does not include the model's answers because those predictions are produced during evaluation, not part of the dataset itself. This separation helps give a realistic estimate of how the model will perform in the real world.