For an opinion to be substantiated, you need supporting evidence or a reference to validate it. Option A qualifies as it mentions a verifiable fact by suggesting that one can check with the large computer company to see its origin. More evidence would be required to substantiate the claim that small businesses are the backbone of America's strong economy. Option C lacks easily accessible factual support, while D presents a more generalized statement.
In Act 3, Scene 2, both Brutus and Antony address the crowd regarding the assassination of Caesar. Each senator expresses admiration for Caesar and highlights his contributions to the citizens of Rome. Nonetheless, Brutus argues that Caesar's ambition posed a threat to the Roman Republic, while Antony counters that Caesar was a benefactor to Rome and labels the conspirators as dishonorable.