In the context of this conversation, what could replace 'hadn't passed' in this sentence: What would you have done if you _____ your driving test this time?

The correct replacement for "hadn't passed" in the sentence is "didn't pass." This choice maintains the conditional structure implied by the phrase "What would you have done if you...".

Using "didn't pass" fits appropriately because it refers to a hypothetical situation in the past—in this case, the possibility of not passing the driving test. The sentence is structured as a third conditional, which is often used to talk about unreal situations in the past and their possible outcomes. With "didn't pass," the sentence reads smoothly and clearly communicates that the speaker is speculating about a past event that did not happen.

The other options do not align with the conventional structure of the conditional statement. For example, "did pass" implies the opposite situation, while "haven't passed" suggests a present perfect tense that does not fit the context, as it lacks the necessary reference to a completed past event. Similarly, "won't have passed" mixes future and past tenses inappropriately, which would not work in this context. Thus, "didn't pass" is the only option that correctly preserves the intended meaning of the sentence.