Final answer:
The best statement to establish a claim that can be supported by external evidence is 'Cigarette commercials have been shown to induce more children and teenagers to start smoking' as it directly asserts an effect that can be validated by various sources.
Step-by-step explanation:
The statement that best establishes a claim, making an argument that can be supported with evidence from outside media sources, is D) Cigarette commercials have been shown to induce more children and teenagers to start smoking. This claim plainly states a causative effect that can be substantiated with statistical data, scientific studies, or historical records from anti-smoking campaigns or health reports. Such evidence could include the reports of the Royal College of Physicians of London and the United States Surgeon-General, which highlight the harmful effects of cigarette smoking on health. Moreover, public programs designed to discourage cigarette use or help people quit, such as anti-smoking advertising campaigns, have demonstrated effectiveness in reducing smoking, particularly among the youth whose smoking habits appear to be more responsive to these interventions, as mentioned in the provided excerpts.