单选题 Which of the following, if true, is the most logical completion of the argument below?
The tax system of the Republic of Grootland encourages borrowing by granting its taxpayers tax relief for interest paid on loans. The system also discourages saving by taxing any interest earned on savings. Nevertheless, it is clear that Grootland's tax system does not consistently favor borrowing over saving, for if it did, there would be no______.

A、 tax relief in Grootland for those portions of a taxpayer's income, if any, that are set aside to increase that taxpayer's total savings
B、 tax relief in Grootland for the processing fees that taxpayers pay to lending institutions when obtaining certain kinds of loans
C、 tax relief in Grootland for interest that taxpayers are charged on the unpaid balance in credit card accounts
D、 taxes due in Grootland on the cash value of gifts received by taxpayers from banks trying to encourage people to open savings accounts
E、 (E) taxes due in Grootland on the amount that a taxpayer has invested in interest-bearing savings accounts

【正确答案】 A

【答案解析】[解析] 本题虽是最后一题，但其难度并不大，主要在于阅读。请自己思考(A)正确的原因。
tax relief 税收减免
tax due 应付税，税款
unpaid balance 未支付余额