A 58-year-old male presents with confusion, right-sided weakness, and slurred speech. his airway is patent, and his breathing is adequate. His wife is present and is very upset. Which of the following has the most immediately priority?

a. Documenting all of his current medications
b. Asking his wife when she noticed the symptoms
c. Obtaining a complete set of baseline vital signs
d. Administering glucose to rule out hypoglycemia