问题
单项选择题
An analyst does research about a bond's indenture. Which of the following is an example of a affirmative covenant（）
A. Limit additional borrowings unless certainfinancial conditions are met.
B. Prohibit the same assets back several debt issues simultaneously.
C. Maintain of current ratio above 2.5.
答案
参考答案：C
解析：
债券契约中有肯定性条款和否定性条款，选项A和B都是否定性的，只有选项C保持流动性比率大于2.5，属于肯定性条款。