Final answer:
Cyanosis is an example of a sign; it's an objective evidence of disease, unlike symptoms such as nausea, dizziness, and chest pain which are subjective and reported by the patient.
Step-by-step explanation:
Among the options provided, cyanosis is an example of a sign. Unlike symptoms, which are subjective and cannot be clinically confirmed or objectively measured, signs are objective evidence of disease that can be observed and measured by someone other than the patient. Cyanosis refers to the bluish or purplish discoloration of the skin and mucous membranes, which is due to low oxygen saturation in the blood and can be observed by a healthcare provider. Other options such as nausea, dizziness, and chest pain are considered symptoms because they are experiences reported by the patient that cannot be directly observed by a clinician.