Which type of research design is most appropriate for investigating cause-and-effect relationships?

Correct Answer: C

Rationale: The correct answer is C: Experimental research design. This design is most appropriate for investigating cause-and-effect relationships because it involves manipulating an independent variable to observe the effect on a dependent variable, allowing for establishing causal relationships. Descriptive research (A) is used to describe characteristics of a population but does not establish causation. Correlational research (B) examines relationships between variables but does not determine causation. Qualitative research (D) focuses on exploring attitudes, beliefs, and experiences but does not typically investigate cause-and-effect relationships.

Correct Answer: A

Rationale: The correct answer is A because it is recommended to change toothbrushes every 3 months to maintain effective cleaning and prevent bacterial buildup. Regularly changing toothbrushes ensures the bristles remain firm and effective in removing plaque and bacteria. Choice B of changing toothbrushes every birthday is not as precise and may result in using a worn-out toothbrush. Choices C and D are left blank as they are irrelevant and not related to the recommended practice of changing toothbrushes regularly.

Correct Answer: B

Rationale: The correct answer is B, wear goggles. Goggles provide eye protection against airborne particles, preventing entry through the mucous membranes. Wearing a mask alone does not protect the eyes, leaving them vulnerable to infection. Choice C and D are not given, so they are automatically incorrect. In summary, wearing goggles is crucial for comprehensive protection against airborne diseases, while wearing a mask alone may not provide complete protection.

Correct Answer: B

Rationale: The correct answer is B: File nails straight. Filing nails straight helps prevent nails from weakening and breaking. It maintains nail strength and shape. Following the curve (choice A) can cause uneven edges and weaken nails. Choices C and D are not provided, but filing nails in a straight motion is generally recommended for healthy nail care.

Correct Answer: B

Rationale: The correct answer is B because urine culture and sensitivity are used to identify the specific organism causing the infection in the urinary tract. This is crucial for selecting the most effective antibiotic treatment. Choice A is incorrect because urine culture does not analyze elements like blood and pus, but rather focuses on microbial growth. Choices C and D are incomplete and do not provide a relevant explanation for the purpose of urine culture and sensitivity.