The clock-drawing test (CDT) has become a standard cognitive screening tool around the world. Like all cognitive screening tests, it is designed to detect early brain changes to determine if a person may be experiencing dementia. Which of the following statements most accurately depicts the usefulness of this test?

Choice A reason: While the CDT is somewhat affected by education, it should not be used alone for diagnostic purposes because it is a screening tool, not a definitive test. Choice B reason: The CDT does not measure IQ; it is designed to assess multiple domains of cognitive function including executive functioning, visuospatial abilities, and planning. Choice C reason: The CDT is quick to administer, non-invasive, and provides assessment across multiple cognitive domains, making it valuable for early detection of cognitive impairment. Choice D reason: The CDT does not specifically predict focal brain degeneration; it is a general screening tool rather than a neuroimaging substitute.