Pierre, a cash basis, unmarried taxpayer, had $1,400 of state income tax withheld during 2016. also in 2016, pierre paid $455 that was due when he filed his 2015 state income tax return and made estimated payments of $975 towards his 2016 state income tax liability. when pierre files his 2016 federal income tax return in april 2017, he elects to itemize deductions, which amount to $10,650, including the state income tax payments and withholdings, all of which reduce his taxable income. as a result of overpaying his 2016 state income tax, pierre receives a refund of $630 in 2017. the standard deduction for single taxpayers for 2015 was $6,300.a. what is pierre’s 2016 state income tax deduction? b. how much of the $630 will pierre include in his 2017 gross income?