Choose the correct word: The gang robbed three banks in the same city and all at about the same time. Not ____________, they were caught by the police during the fourth attempt.

In the context of the sentence, the correct choice "surprisingly" functions as an adverb that describes the situation regarding the gang's capture by the police. When saying, "Not surprisingly, they were caught by the police," it implies that their capture was anticipated or expected based on their previous actions.

Using "surprisingly" fits seamlessly with the natural flow of the sentence, indicating that their arrest was not surprising given the circumstances. This explains why they were caught during their fourth attempt after already successfully robbing three banks.

The other options, while they share some semantic similarities with "surprisingly," do not convey the same meaning in this particular context. For example, "surprise" is a noun, which would not grammatically work in this context as it does not describe the situation directly. "Unexpectedly" implies a lack of expectation but does not fit well with the intended meaning of the sentence; it would suggest that their capture was unexpected, which contrasts with the prior context where they had already shown a pattern of robbing banks. "Unpredictably" has similar issues as it suggests randomness rather than a commentary on their behavior leading up to the arrest, which is not the focus of the sentence.

Thus, "surprisingly