The c.d.f. of a discrete random variable $X$ is $\begin{array}{|c|c|c|c|c|c|c|c|c|} \hline X & -3 & -1 & 0 &…

The cumulative distribution function defines $F(x) = P(X \leq x)$ for discrete $X$. Since $-3$ is the minimum value provided, $P(X = -3) = F(-3) = 0.1$.

Probability $P(X < 0)$ considers all outcomes strictly less than zero, namely $-3$ and $-1$. Using the jump at $x = -1$, we find $P(X = -1) = F(-1) - F(-3) = 0.3 - 0.1 = 0.2$. Summing gives $P(X < 0) = 0.1 + 0.2 = 0.3$.

Forming the ratio yields $\frac{P(X = -3)}{P(X < 0)} = \frac{0.1}{0.3} = \frac{1}{3}$, corresponding to option B.