The correct answer is: C. They are not allowed to run away.
The sentence “We will not allow them to run away” is in the present tense. This means that the speaker is making a statement about the present, not the past or future. The other options are all in the past tense, which would not make sense in this context.
Option A, “They will not be allowed to run away by us,” is in the passive voice. This means that the focus of the sentence is on the action (running away) rather than the person doing the action (us). In this case, the speaker is not interested in who is doing the allowing, only in the fact that the people are not allowed to run away.
Option B, “They would not be allowed to run away,” is in the conditional mood. This means that the speaker is making a hypothetical statement about what would happen if something else happened. In this case, the speaker is saying that if the people tried to run away, they would not be allowed to.
Option D, “They were not allowed to run away,” is in the past tense. This means that the speaker is making a statement about the past. In this case, the speaker is saying that the people were not allowed to run away at some point in the past.
Therefore, the correct answer is: C. They are not allowed to run away.