Correct Answer: A

Rationale: The correct answer is A. A low percentage of monocytes can indicate a viral infection. This is crucial information to communicate as it suggests a specific type of infection that may require targeted treatment. Choices B, C, and D do not directly relate to an infectious process and are within normal ranges, so they are not as urgent to communicate to the healthcare provider in this context.

Correct Answer: C

Rationale: The correct answer is C: cobalamin (vitamin B12). Methotrexate can lead to a deficiency in cobalamin, resulting in megaloblastic anemia. Therefore, increasing the oral intake of cobalamin is essential to address this deficiency. Choice A, iron, is incorrect because megaloblastic anemia caused by methotrexate is not typically due to iron deficiency. Choice B, folic acid, is also incorrect as methotrexate does not directly cause folic acid deficiency. Choice D, ascorbic acid (vitamin C), is incorrect as it is not directly related to megaloblastic anemia caused by methotrexate; instead, cobalamin is the key vitamin that needs attention.

Correct Answer: D

Rationale: A low white blood cell (WBC) count in an older patient is concerning as it indicates a potential compromise in the patient's immune function. White blood cells are crucial for fighting infections and a low count could lead to an increased risk of infections. Hematocrit, hemoglobin, and platelet count are important parameters to assess, but a low WBC count takes priority in this case due to its direct impact on immune health.

Correct Answer: C

Rationale: The correct answer is C: 'Do you take medication containing salicylates?' Petechiae are tiny, pinpoint, red or purple spots on the skin due to bleeding under the skin. Salicylates, which are found in medications like aspirin, interfere with platelet function and can lead to petechiae and ecchymoses. Asking about salicylate-containing medications is crucial in this situation. Choices A, B, and D are incorrect because they are not directly related to the development of petechiae.

Correct Answer: B

Rationale: The correct answer is B: Platelet count. The platelet count is severely decreased, indicating a risk for spontaneous bleeding, which is a critical condition requiring immediate attention. While heart rate, abdominal pain, and white blood cell count are important, a severely decreased platelet count poses a more imminent threat to the patient's health and requires urgent communication to the healthcare provider. The nurse should prioritize addressing this potentially life-threatening issue to ensure prompt intervention and management.