To diagnose a patient with lactic acidosis, analysis must be used:

Correct Answer: C

Rationale: Elevated blood lactate levels confirm lactic acidosis.

Correct Answer: B

Rationale: Cutaneous leukocytoclastic vasculitis affects small vessels, causing purpura.

Correct Answer: C

Rationale: Carvedilol has both beta and alpha-blocking activity, beneficial in heart failure.

Correct Answer: C

Rationale: Sodium nitroprusside is the drug of choice for hypertensive crisis due to rapid action.

Correct Answer: A

Rationale: The aortic semilunar valve prevents backflow of blood into the left ventricle during ventricular diastole.