The correct distinguishing feature among the choices provided is: A postulate is assumed to be true, and it does not have to be proven.
To clarify:
- Postulates (or axioms) are statements accepted as true without proof and serve as the foundational building blocks for further reasoning in mathematics and logic.
- Theorems are statements that have been proven to be true based on postulates, definitions, and previously established theorems.
- Definitions provide precise meanings for terms and concepts but do not intrinsically hold truth or require proof.
- Conjectures are propositions that are suspected to be true based on observations but have not yet been proven or disproven.
Given these distinctions, the response “A postulate is assumed to be true, and it does not have to be proven” is accurate.