Margo has $2,100 withheld from her wages for state income taxes during 2012. In March of 2012, she paid $300 in additional taxes for her 2011 state tax return. Her state income tax liability for 2012 is $2,500 and she pays the additional $400 when she files her 2012 state tax return in April of 2013. What amount should Margo deduct as an itemized deduction for state income taxes on her 2012 federal income tax return, assuming she elects to deduct state and local income taxes?
a. $2,100
b. $2,500
c. $2,800
d. $2,400
e. None of the above