Which pronoun would correctly fill in the blank in the following sentence? The government levied taxes on _____ citizens.

The correct pronoun to fill in the blank is "its." This pronoun appropriately shows possession, indicating that the taxes are being levied on the citizens that belong to the government. The structure of the sentence calls for a possessive pronoun because it implies a relationship between the government and its citizens, suggesting that the citizens are under the jurisdiction of that government.

Using "its" fits grammatically and contextually, as it reflects the relationship between the governing body and the people it governs. Other pronouns, while they might seem relevant in different contexts, do not maintain the same possessive meaning or grammatical structure needed for this particular sentence.