Correct Answer: A

Rationale: Folate is crucial before conception to prevent neural tube defects. Neural tube development occurs early in pregnancy, often before a woman knows she is pregnant.

Correct Answer: C

Rationale: The correct answer is C, Larynx. The larynx is part of the respiratory system, responsible for voice production and breathing. The alimentary canal is involved in the digestive process and includes structures like the oral cavity (mouth), pharynx, and esophagus. Choices A, B, and D are parts of the alimentary canal, where digestion occurs, making them incorrect answers.

Correct Answer: B

Rationale: Iron deficiency is the most common nutrient deficiency globally. It leads to anemia and affects many populations, especially women and children. Magnesium, selenium, and zinc deficiencies are important, but they are not as prevalent as iron deficiency on a global scale.

Correct Answer: C

Rationale: The first statement is true; nonnutritive sweeteners do not promote caries. However, the second statement is false because products with nonnutritive sweeteners should still be consumed in moderation.

Correct Answer: C

Rationale: The correct answer is C, 'Evidence-based.' Evidence-based practices refer to medical practices that have been thoroughly evaluated and supported by scientific research. Meta-analysis (A) involves statistical analysis that combines the results of multiple studies. Systematic reviews (B) are comprehensive reviews that synthesize evidence from multiple studies. Observational studies (D) are research methods where researchers observe subjects in their natural environment.