The Number of Cars Waiting at a Certain Residential Neighborhood

Multiple Choice

The number of cars waiting at a certain residential neighborhood stoplight is observed at 6:00 a.m. on 160 different days. The observed sample frequencies are shown here: $$\begin{array} { | l | r | r | r | r | } \hline \text { Number of cars waiting } & 0 & 1 & 2 & 3 \\\hline 60 & 60 & 50 & 30 & 20 \\\hline\end{array}$$ Under the null hypothesis of a uniform distribution, the expected number of days we would see 0 cars is:

A) 10.
B) 20.
C) 30.
D) 40.