Which statement best describes the component-cause model?

• A. A single factor alone always causes disease.
• B. A necessary cause is identical to a component-cause.
• C. A disease arises when a sufficient combination of component-causes is present.
• D. All diseases have multiple necessary causes.

Answer: (C)

The component-cause model envisions disease as the result of one complete sufficient cause, which is a set of component causes. A disease occurs when that complete set is present, meaning the right combination of factors comes together to form a sufficient cause. Each component contributes to that pathway, but no single factor by itself explains all cases. That’s why the statement describing a disease arising from a sufficient combination of component-causes is the best description.

This differs from believing a single factor always causes disease, since many diseases require multiple factors to come together. It also separates a component-cause from a necessary cause; a necessary cause must be present for the disease, but a component-cause is part of a larger sufficient set, and there can be multiple different sufficient sets. Not all diseases have multiple necessary causes, so saying all do isn’t accurate.