Louis files as a single taxpayer. In April of this year he received a $1,200 refund of state income taxes that he paid last year. How much of the refund, if any, must Louis include in gross income under the following independent scenarios? Assume the standard deduction last year was $12,000.

a. Last year Louis claimed itemized deductions of $12,095. Louiss itemized deductions included state income taxes paid of $2,075 and no other state or local taxes.

b. Last year Louis had itemized deductions of $10,740 and he chose to claim the standard deduction. Louiss itemized deductions included state income taxes paid of $2,075 and no other state or local taxes.

c. Last year Louis claimed itemized deductions of $13,820. Louiss itemized deductions included state income taxes paid of $3,945 and no other state or local taxes.

PLEASE EXPLAIN THE ANSWER IN DETAIL.