What is the burden of proof in a professional negligence case?

In a professional negligence case, the burden of proof is established as "preponderance of the evidence." This standard requires that the evidence presented by one party be more convincing than the evidence presented by the opposing party. In other words, it must be shown that it is more likely than not that the defendant's actions (or lack of actions) resulted in harm to the plaintiff. This standard is commonly used in civil cases, including those involving claims of negligence, because it reflects the balance of probabilities rather than requiring absolute certainty.

Other standards referenced in the options serve different contexts; for instance, "clear and convincing" is a higher standard often used in certain civil cases, requiring a greater level of certainty than preponderance but less than beyond a reasonable doubt, which is the threshold for criminal cases. The phrases "beyond all reasonable doubt" and "beyond a reasonable doubt" indicate the highest level of certainty necessary in criminal trials to establish guilt. Thus, the choice of "preponderance of the evidence" accurately reflects the appropriate standard of proof required in cases of professional negligence.