Given that the equation of line $l$ is $3 x - 4 y + 1 = 0$, which of the following is a parametric equation of $l$? ( )
A. $\left\{ \begin{array} { l } x = 4 + 3 t \\ y = 3 - 4 t \end{array} \right.$
B. $\left\{ \begin{array} { l } x = 4 + 3 t \\ y = 3 + 4 t \end{array} \right.$
C. $\left\{ \begin{array} { l } x = 1 - 4 t \\ y = 1 + 3 t \end{array} \right.$
D. $\left\{ \begin{array} { l } x = 1 + 4 t \\ y = 1 + 3 t \end{array} \right.$