Ellen is a single taxpayer. Ellen's employer pays $150 per month ($1,800 this year) for her health insurance. During the year, Ellen had medical expenses of $3,500 and the insurance company paid $2,000 of the expenses. How much of the above amounts, if any, must be included in Ellen's gross income?

A. $0 B. $2,000 C. $1,800 D. $3,500 E. $5,300