Chloe and Nathan are married and have two children. Nathan's employer provides health insurance, which covers Nathan and his family. The employer pays 80% of the premiums, and Nathan pays the remaining 20% out of his salary. During the year, Nathan's family incurs $15,000 of medical expenses. The insurance company pays $5,000 directly to physicians and reimburses Nathan for the remaining $10,000. Which of these, if any, should Nathan include on his return as income? a. None of the items listed b. Premiums paid by his employer c. $10,000 paid to him by the insurance company d. $5,000 paid directly to doctors by the insurance company