[单选题]
In a first order reaction, the4f3z1(sod7r+ao kq pi concentration [5un3t* v ,iblrA] of a given reactant can be determined abit* v 3,ruln5t time t, according to the equation below, where [A]$_o$ is the initial concentration of A and k is the rate constant.
ln[A]=-kt+ln[A]$_o$
A. Independent variable
B. Dependent variable
C. y-intercept
D. Gradient
