The response is effective because it directly addresses the claim about smartphones and cancer risk with scientific evidence. It cites reputable sources, including the FDA and the National Cancer Institute, which bolster its credibility. The explanation clarifies that smartphones emit non-ionizing radiation, which does not damage DNA. Additionally, it highlights that extensive research has found no significant cancer risk associated with cell phone use. This combination of evidence, expert sources, and clear reasoning makes the response a solid refutation of the claim.