In memory tests, older adults often perform ____ than younger adults. These results have been criticized for lacking:

The correct answer is B. worse; ecological validity.

In memory tests, older adults often perform worse than younger adults, and critics argue that these tests may lack ecological validity, meaning the findings might not accurately reflect real-world memory performance or situations outside of the test environment. This suggests that the way memory is tested may not properly represent the way people use their memory in everyday life.