Compare the options provided: Evaluate each statement in the problem. For example, 'Benign tumors grow faster than malignant tumors' is incorrect because benign tumors generally grow slower. Similarly, 'Benign tumors are caused by viruses, while malignant tumors are caused by bacteria' is incorrect because tumors are not typically caused by these pathogens. Lastly, 'Benign tumors are always fatal, while malignant tumors are harmless' is incorrect because benign tumors are rarely fatal, and malignant tumors are dangerous.