Suppose There Are Two People in a Society That Has

Suppose there are two people in a society that has a 50% income tax.Both people have pretax incomes of $40,000.In period 1,there was no tax deduction; Lillian gave $6,000 to charity,and Susie gave $4,000 to charity.In period 2,the government makes charitable donations tax deductible,and Lillian gives $8,000 to charity.What is the amount Susie must give in period 2 so that the marginal impact of the tax break is exactly twice the inframarginal impact of the tax break?

A) $7,000
B) $8,000
C) $10,000
D) $12,000