Explanation:

- Option 1: Imprisonment can involve hard labor, depending on the legal system and the nature of the sentence. Some jurisdictions include labor as part of rehabilitation or punishment.

- Option 2: Imprisonment certainly involves confinement to a facility such as a jail or prison. This is a fundamental aspect of what imprisonment entails.

- Option 3: The nature of imprisonment can differ. It may vary from maximum-security, high-restriction settings to more open, less stringent environments, depending on the severity of the crime or the legal system.

- Option 4: Since imprisonment encompasses hard labor, confinement, and variations based on context, all options describe aspects of imprisonment.

Option 4: All of them.

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