Which of the Following Distributions Is Suitable to Model the Length

Short Answer

Which of the following distributions is suitable to model the length of time that elapses before the first telephone call is received by a switchboard? $\begin{array}{|l|l|}\hline\text { A. } & \text { Exponential. } \\\hline \text { B. } & \text { Normal. } \\\hline \text { C. } & \text { Poisson. } \\\hline \text { D. } & \text { Uni form. } \\\hline\end{array}$