The following data show the number of passengers in cars at a school football game:


5, 3, 4, 5, 4, 4, 2, 3, 1, 3, 4, 4, 5, 5


The data have been organized into a dot plot, as shown below:


A dot plot with integers 1 to 5 is shown. It is labeled Passengers, and titled Passengers in Cars. There is 1 dot above 1, 1 dot above 2, 2 dots above 3, 5 dots above 4, and 4 dots above 5.


For which number are the data plotted incorrectly?



a

2


b

3


c

4


d

5