In the Probability Table Below, Which Value Is a Marginal

Multiple Choice

In the probability table below, which value is a marginal probability? ?? $$\begin{array} { | l | l | l | c | } \hline & { \text { Completed } } \\\hline \text { Obstacle Course Level } & \text { No } & \text { Yes } & \text { Total } \\\hline \text { Challenging } & 0.4 & 0.3 & 0.7 \\\hline \text { Easy } & 0.1 & 0.2 & 0.3 \\\hline \text { Total } & 0.5 & 0.5 & 1 \\\hline\end{array}$$

A) 0.1
B) 1
C) 0.5
D) 0.4