The reason for choosing option (4) "based on the first impression" as the appropriate option for the underlined foreign word "prima facie" in the sentence is as follows:

- "Prima facie" is a Latin term commonly used in legal contexts to refer to evidence or a situation that appears to be true on the first impression or initial examination.

- In this sentence, "prima facie evidence" means evidence that, at first glance or based on initial observations, suggests that someone was involved in fraud. It implies that further investigation may be needed to confirm this evidence.

- Option (4) "based on the first impression" effectively captures the meaning of "prima facie" in the context of the sentence, making it the most suitable choice.