An unmarried taxpayer itemized deductions in 2009. The taxpayer's itemized deductions were $6,250; the standard deduction amount was $5,700. Included in the taxpayer's itemized deductions were $3,700 of state income tax withheld. In 2010, the taxpayer receives an $800 refund check from the state government. What amount must the taxpayer include in gross income in 2010?
a. $0.
b. $550.
c. $750.
d. $800.
e. None of the above