Respuesta :
Subject-verb agreement is the part that makes the sentence. The correct blank is 'were released.'
What is the subject-verb agreement?
The subject and the verb of the sentence must have the same plural or the singular form and must agree with each other in the quantitative form. So, a singular subject goes with a singular verb, and a plural subject goes with a plural verb.
In the sentence, the subject, 'prisoners' is plural, so the verb used will be 'were released' as it uses the correct verb and tense in the sentence.
Therefore, the correct blank is 'were released.'
Learn more about the subject-verb agreement here:
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