![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
Unit elastic demand means that the
A.
ratio of a change in the quantity demanded to a change in the price equals 1.
B.
ratio of a percentage change in the quantity demanded to a percentage change in the price equals 1.
C.
demand curve is vertical.
D.
demand curve is horizontal.