Correct Answer: C

Rationale: The correct answer is C: Regulating leptin, an appetite-controlling hormone. In the provided passage, it is stated that human growth hormone (HGH) is essential for regulating metabolism, building muscle, facilitating calcium retention, and stimulating the immune system. However, leptin is not mentioned as directly regulated by HGH. Instead, the passage discusses how inadequate sleep can lead to lowered levels of leptin, affecting appetite control. Choices A, B, and D are all roles of HGH explicitly mentioned in the passage, making them incorrect answers. Therefore, C is the correct choice as it was not directly linked to HGH in the passage.

Correct Answer: A

Rationale: The passage discusses the long-term effects of environmental toxins, which aligns with this main idea.

Correct Answer: B

Rationale: The best summary of the passage is choice B. The passage discusses concerns about the impact of high fructose corn syrup (HFCS) on health, particularly its link to obesity. It mentions a recent study on rats that confirms suspicions about HFCS contributing to unhealthful weight gains. Choices A, C, and D are incorrect as they introduce recommendations or implications not explicitly mentioned in the passage. Choice A goes beyond the information by stating that scientists recommend removing HFCS from grocery products, choice C suggests that using HFCS is preferable until more research is done, and choice D implies immediate healthful results on overweight patients by avoiding HFCS, as suggested by the AMA, which is not supported by the passage.

Correct Answer: B

Rationale: The correct answer is B. The passage clearly states that there are treatments for hypertension, so the statement that there is presently no reliable treatment for hypertension cannot be inferred from the text. Choice A can be inferred from paragraph 3 where it mentions losing weight to decrease blood pressure. Choice C can be inferred from paragraph 1 where it states that African Americans are more likely to have hypertension. Choice D can be inferred from paragraph 2 where it explains that older people are most often diagnosed with hypertension due to changes in blood vessels as they age.

Correct Answer: D

Rationale: The primary purpose is to analyze the various aspects of concussions.