Final answer:
Factual statements, statistics, and expert testimony are considered strong, verifiable evidence for backing a claim, while a strong opinion is not, as it is subjective and cannot be empirically verified.
Step-by-step explanation:
Convincing evidence to back a claim includes several types of support, but not all are equally effective. Among the options provided, factual statements, statistics, and expert testimony are all forms of evidence that can be verified and are considered strong backing for an argument. However, strong opinion is not typically included as convincing evidence because, while it can provide a perspective or illustrate a belief, it cannot be verified in the same way as the other forms of evidence. Strong opinions are often subjective and not based on empirical data or expert analysis, which diminishes their credibility in an argument when compared to objective evidence.