In the following sentence, fill in the blank with the most appropriate word: "The criminal was released on ___________ for a few days so that he could spend time with his ailing mother."

Introduction / Context:
This question tests your understanding of legal and semi legal vocabulary related to the temporary release of prisoners. The sentence is The criminal was released on ___________ for a few days so that he could spend time with his ailing mother. The key idea is temporary release under certain conditions, while the person is still technically serving a sentence.

Given Data / Assumptions:

• The subject is a criminal already in custody or serving a sentence.
• He is released for a few days only, not permanently.
• The purpose is compassionate: to visit his ailing mother.
• Options: parole, guarantee, grant, mercy, reprieve.

Concept / Approach:
Parole is the conditional release of a prisoner before the full sentence has been served, often on good behaviour, and subject to certain conditions. It implies that the sentence continues but the person is allowed out under supervision. The phrase released on parole is a standard legal collocation. Other options either do not fit the legal context or do not describe the type of release mentioned in the sentence.

Step-by-Step Solution:
Step 1: Identify that the person is a criminal, so legal terminology is required.Step 2: Understand that the release is temporary and conditional.Step 3: Recall the expression released on parole, which is frequently used in legal and news reports.Step 4: Compare with guarantee, grant, mercy, and reprieve, and see that none of these form a natural phrase released on X.Step 5: Select parole as the most accurate and idiomatic choice.

Verification / Alternative check:
In legal language, we commonly read headlines such as Prisoner released on parole for good behaviour. The word parole directly indicates conditional release, often involving regular reporting to authorities. In contrast, grant and mercy are too vague, and guarantee is about assurance or security, not release. Reprieve refers more to a delay or cancellation of punishment than to temporary release for a few days. Thus, only parole fits perfectly.

Why Other Options Are Wrong:

• guarantee: Means a promise or assurance. One can give a guarantee, but a criminal is not released on guarantee in standard usage.
• grant: Refers to something given, such as a sum of money or a permission. It does not form a fixed legal phrase released on grant.
• mercy: Refers to kindness or compassion but is not the specific legal term for conditional release.
• reprieve: Means a delay in carrying out a punishment, especially execution, not a temporary release for visiting family.

Common Pitfalls:
Some learners confuse parole with bail or reprieve. Bail generally applies before conviction, while parole usually comes after part of a sentence has been served. Reprieve is mainly used for delaying severe punishments. Paying attention to the phrase released on and the context of a criminal already serving time will guide you to the correct choice.

Final Answer:
The word that correctly completes the sentence is parole.