A nurse is assessing a client who has asthma. Which of the following areas should the nurse evaluate as the most reliable indicator of central cyanosis?

A. The conjunctivae can show signs of cyanosis but is not the most reliable indicator of central cyanosis. B. Ear lobes may show peripheral cyanosis but are not reliable for central cyanosis. C. The soles of the feet are not typically assessed for cyanosis in this context. D. The oral mucosa is the most reliable indicator of central cyanosis, as it reflects the oxygenation status of the blood more accurately.