In evaluating arguments, which choice best describes the function of an assumption in most deductive reasoning tests?

• A. Conclusion
• B. Premise
• C. Evidence
• D. Rebuttal

Answer: (B)

An assumption in deductive reasoning is the taken-for-granted premise that makes the conclusion follow from the given information. It’s the hidden step the argument relies on—often unstated—that connects the stated facts to the conclusion.

Think of it as the starting point the reasoning treats as true to bridge the gap between what’s given and what’s claimed. On many tests, spotting this assumption helps you judge whether the conclusion truly follows; if the assumption isn’t reasonable, the argument weakens.

For example, if someone argues that a diet reducing calories will lead to weight loss, and they say “this plan reduces calories,” the assumption is that there won’t be other factors preventing weight loss and that the plan is followed as intended. This assumption is the premise that makes the conclusion (you will lose weight) work.

The conclusion is the claim being proven, not what’s taken for granted. The evidence (when present) supports the conclusion but isn’t the assumed bridge itself. A rebuttal would be an opposing point, not the premise that the argument depends on.