Correct Answer: A

Rationale: Flattened T waves are an early sign of hypokalemia on an ECG. In hypokalemia, the T waves may flatten and eventually invert. Elevated ST segments are not typically associated with hypokalemia. Prominent U waves are seen in conditions like hypokalemia, but they are not considered an early sign. A widened QRS complex is more commonly associated with hyperkalemia rather than hypokalemia.

Correct Answer: A

Rationale: Flattened T waves are an early sign of hypokalemia on an ECG. Hypokalemia primarily manifests as flattened T waves on an ECG. While prominent U waves can be seen in hypokalemia, they are not as specific as flattened T waves. ST elevation is more commonly associated with conditions like myocardial infarction rather than hypokalemia. Wide QRS complexes are typically not a feature of hypokalemia on an ECG.

Correct Answer: A

Rationale: Osteomyelitis often manifests as localized pain, swelling, and erythema due to infection in the bone. These symptoms are characteristic of inflammation and infection in the bone tissue. Elevated white blood cells (Choice B) may be present as part of the body's immune response to the infection but are not specific manifestations of osteomyelitis. Elevated calcium levels (Choice C) and low potassium levels (Choice D) are not typically associated with osteomyelitis.

Correct Answer: A

Rationale: A thrombotic stroke presents with a gradual loss of function on one side of the body due to a clot blocking blood flow to the brain. This gradual onset distinguishes it from a hemorrhagic stroke with sudden symptoms like loss of consciousness (Choice B), and from other conditions like migraine, which may present with severe headache and vomiting (Choice D). Nausea (Choice C) is not typically a primary symptom associated with a thrombotic stroke.

Correct Answer: A

Rationale: Flattened T waves are an early indicator of hypokalemia on an ECG. Hypokalemia primarily presents with flattened T waves, not prominent U waves, widened QRS complexes, or tall T waves. Prominent U waves are associated with hypokalemia only in severe cases. Widened QRS complexes are more indicative of hyperkalemia, while tall T waves are seen in hyperkalemia as well.