Correct Answer: C

Rationale: The Transaction-Based Model, proposed by R.S. Lazarus, is the most relevant model of stress in the context of a client facing communication issues with his mother. This model takes into consideration individual differences and cognitive processes that occur between a stressor and the individual's response. It emphasizes the importance of how the individual perceives and interprets the stressor, incorporating mental and psychological components. In this scenario, the client's difficulties in communicating with his mother involve complex cognitive processes and individual perceptions, making the Transaction-Based Model the most suitable choice. The other options are not as relevant in this context: the Adaptation Model focuses on adjustment to stress over time, the Stimulus-Based Model emphasizes external factors as stressors, and Selye's Model of Stress mainly centers on the physiological response to stress.

Correct Answer: B

Rationale: Head lag is a developmental milestone that should be resolved by 4 months of age. Continuing head lag at 6 months of age may indicate potential developmental delays or muscle weakness. The correct answer, 'Nausea, vomiting, diarrhea, or constipation, and stomach cramps,' reflects symptoms that could be associated with developmental delays or underlying health conditions. Dizziness and orthostatic hypotension (Choice A) are unlikely to be directly related to head lag. Choices C and D present symptoms that are unrelated to the issue of continued head lag at 6 months of age.

Correct Answer: D

Rationale: The correct test to differentiate between sickle cell trait and sickle cell disease is hemoglobin electrophoresis. This test separates different types of hemoglobin based on their electrical charge, allowing for the identification of specific hemoglobin variants like HbS in sickle cell disease. Sickle cell preparation and Sickledex are not specific tests for this differentiation. While a peripheral smear can show sickle cells, it does not provide a definitive differentiation between the trait and the disease as it doesn't identify the specific hemoglobin variant present.

Correct Answer: C

Rationale: When folic acid is given without determining the underlying cause of anemia, the symptoms of pernicious anemia may be masked, potentially delaying the correct treatment. Folic acid alone does not protect against the central nervous system changes seen in pernicious anemia, which are related to Vitamin B12 deficiency. Folic acid and Vitamin B12 are both crucial for cell growth and division. Administering folic acid without knowing the specific type of anemia could lead to a delay in addressing the root cause. Option A is incorrect because folic acid is essential for erythropoiesis, the production of red blood cells. Option B is incorrect as excessive folic acid can cause toxicity, but it is not the primary concern in this context. Option D is incorrect because folic acid treatment for anemia does not directly impact intrinsic factor, which is related to Vitamin B12 absorption.

Correct Answer: A

Rationale: Metformin is classified as an antihyperglycemic agent because it works by reducing hepatic glucose output and decreasing glucose absorption from the gut, thereby preventing hyperglycemia. Choice B, a hypoglycemic agent, is incorrect as hypoglycemic agents stimulate insulin production, which is not the mechanism of action of metformin. Choice C, an insulin analogue, is incorrect as metformin is not a type of insulin but a distinct medication. Choice D, a pancreatic alpha cell stimulant, is incorrect as metformin does not stimulate any pancreatic cells, but rather acts on the liver and gut to lower blood sugar levels.