To determine the best support for a substantiated opinion, we need to evaluate the options based on their reliability and credibility.

Solution By Steps

Step 1: Evaluate the reliability of personal opinions

Personal opinions are subjective and may lack evidence or broad acceptance, making them less reliable for substantiating an opinion.

Step 2: Assess the value of individual thoughts

Individual thoughts, similar to personal opinions, are subjective and may not be widely accepted or supported by evidence.

Step 3: Consider the credibility of expert opinions

Expert opinions are based on specialized knowledge and often supported by research and evidence, making them highly credible and reliable for substantiating an opinion.

Step 4: Analyze the strength of common beliefs

Common beliefs may or may not be based on factual evidence and can vary widely among different groups, reducing their reliability as a basis for substantiated opinions.

Final Answer

A substantiated opinion is best supported by expert opinions.