The probability of occurrence of an event is ____.

• A.  \[\frac{\text{Number of trials in which an event occured}}{\begin{align}   & \text{Total number of trials - Number of trials in which} \\  & \text{and event occured} \\ \end{align}}\]
• B.         \[\frac{\text{Number of trials in which an event occured}}{\text{Total number of trials}}\]
• C.         \[\frac{\text{Total number of trials}}{\text{Number of trials in which an event occured}}\]
• D.         \[\frac{\begin{align}   & \text{Total number of trials-Number of trials in} \\  & \text{which an event occured} \\ \end{align}}{\text{Number of trials in which an event occured}}\]