sarika(35) is single. her 2020 federal itemized deductions totaled $14,400, of which she claimed $1,000 of state income taxes paid in 2020. she filed her tax return on april 10, 2021, and on may 1, 2021, she received a $1,000 state income tax refund. how much of her 2020 state refund is taxable on her 2021 federal return?