问题如下：
Which of the following statemtents about unit elastic on demand curve is most likely correct ?
选项：
A. Total revenue achieve its minimum value.
B. Total revenue is between it minimum value and maximal value.
C. Total revenue achieve its maximal value.
解释：
C is correct.
When own-price elasticity is equal to -1, total revenue achieve its maximal value.
请问此题的问题，再加上正确答案，联起来翻译成中文，是如何表达？