What evidence was the basis of the tourist’s claim against the casino?

The correct option highlights that the basis of the tourist's claim against the casino relied on testimony that was deemed inadmissible by the judge. In civil procedure, the admissibility of evidence is crucial as it determines what information can be considered by the court when making a ruling. If testimony is ruled inadmissible, even if it may seem relevant or compelling, it does not contribute to establishing the case for either party.

In this context, the tourist might have attempted to present testimony to support their claim, but if the judge found that the evidence did not meet legal standards—perhaps due to irrelevance, lack of foundation, or it being hearsay—it would not be usable in court. This ruling directly impacts the outcome of the claim and, thus, serves as the essential basis for the tourist's case against the casino.

Recognizing the roles and limitations of evidence in civil claims is fundamental, as the direction of a case can pivot substantially based on what evidence is ultimately presented to and weighed by the court. This is why focusing on the nature of the evidence being inadmissible is pivotal for understanding the claim's viability.