Which of the Following Best Describes a Function That Assigns

Short Answer

Which of the following best describes a function that assigns a numerical value to each simple event in a sample space? $\begin{array}{|l|l|}\hline A&\text {An expected value.}\\\hline B&\text {The mean. }\\\hline C&\text {A random variable. }\\\hline D&\text {The standard deviation. }\\\hline \end{array}$