Correct Answer: A

Rationale: The main purpose of Recommended Dietary Allowances (RDAs) is to provide guidelines for nutrient intakes that meet the needs of most healthy people. Choice B is incorrect because RDAs aim beyond just survival requirements. Choice C is incorrect because establishing maximum safe levels is the role of Tolerable Upper Intake Levels (ULs). Choice D is incorrect because preventing chronic diseases is more associated with Dietary Reference Intakes (DRIs) like Adequate Intakes (AIs) and Tolerable Upper Intake Levels (ULs). Therefore, the correct answer is A.

Correct Answer: C

Rationale: When an increase in exercise is accompanied by a decrease in body weight, it demonstrates a negative correlation. This means that as one variable (exercise) increases, the other variable (body weight) decreases. Choice A, 'variable effect,' is vague and does not accurately describe the relationship between exercise and body weight. Choice B, 'positive correlation,' is incorrect because in a positive correlation, both variables would increase or decrease together. Choice D, 'randomization effect,' is unrelated to the scenario described.

Correct Answer: A

Rationale: Encouraging joint mobility and physical therapy is crucial in managing juvenile idiopathic arthritis (JIA). This approach helps maintain joint function, reduce stiffness, and improve the overall quality of life for children with JIA. Restricting all forms of exercise (Choice B) is not recommended, as appropriate physical activity is beneficial for joint health and overall well-being. Increasing sugar intake (Choice C) is not a recommended practice for managing JIA, as a healthy diet is important for overall well-being and can help reduce inflammation. Using only oral medications (Choice D) may not be sufficient for managing JIA, as a comprehensive treatment plan often includes a combination of medications, physical therapy, and other interventions to effectively manage the condition.

Correct Answer: A

Rationale: The correct answer is A: Joint swelling and pain. These are the most common initial symptoms of juvenile idiopathic arthritis, typically affecting multiple joints. Skin rash (choice B), gastrointestinal bleeding (choice C), and neurological deficits (choice D) are not typical initial symptoms of juvenile idiopathic arthritis. Skin rash may be seen in other conditions like dermatitis or systemic lupus erythematosus, gastrointestinal bleeding may be associated with conditions like inflammatory bowel disease, and neurological deficits could be indicative of conditions like multiple sclerosis.

Correct Answer: A

Rationale: Wheezing is a common symptom of respiratory infections in infants, often associated with coughing and difficulty breathing. It occurs due to the narrowing of the airways. Choice B, 'High appetite,' is incorrect as respiratory infections usually lead to a decrease in appetite rather than an increase. Choice C, 'Increased thirst,' is incorrect as it is not a typical symptom of a respiratory infection in infants. Choice D, 'Lethargy,' can be a symptom of respiratory infections but is not as specific and common as wheezing.