Ans: B
I is true. Since $L_1$ is on the left of the $y$-axis, the $x$ coordinate of all points on $L_1$ must be negative. Note that the $x$-intercept of $L_1$ is $\dfrac{1}{a}$. Hence, we have
I is true. Since $L_1$ is on the left of the $y$-axis, the $x$ coordinate of all points on $L_1$ must be negative. Note that the $x$-intercept of $L_1$ is $\dfrac{1}{a}$. Hence, we have
$\begin{array}{rcl}
\dfrac{1}{a} & < & 0 \\
a & < & 0
\end{array}$
II is not true. Note that the $x$-intercept of $L_1$ and $L_2$ are $\dfrac{1}{a}$ and $\dfrac{1}{b}$ respectively. Since the $x$-intercept of $L_1$ is lying on the left of the $x$-intercept of $L_2$, then we have
$\begin{array}{rcl}
\dfrac{1}{a} & < & \dfrac{1}{b} \\
b & < & a \\
\end{array}$
III is true. Note that the $y$-intercept of $L_2$ is $\dfrac{1}{c}$. Since the $y$-intercept of $L_2$ is lying above the $x$-axis, then we have
$\begin{array}{rcl}
\dfrac{1}{c} & > & 0 \\
c & > & 0
\end{array}$
