What standard of proof is commonly used in civil trials?

The preponderance of evidence standard is the correct answer because it reflects the level of proof typically required in civil trials. This standard means that a party must present evidence that is more convincing than the evidence presented by the opposing party, essentially tipping the scales in favor of one side. In practical terms, it can be understood as indicating that there is a greater than 50% chance that the claims made by one party are true.

In contrast, the beyond a reasonable doubt standard is primarily used in criminal trials, requiring a much higher threshold of certainty due to the serious implications of criminal convictions. Clear and convincing evidence is also a higher standard than preponderance of evidence and is usually applied in certain civil cases, especially where specific rights or claims are at stake. Probable cause involves a standard used in criminal investigations, particularly when determining whether a warrant should be issued, and is not applicable in civil trials. Thus, the preponderance of evidence standard is specifically appropriate for the context of civil litigation.