What is the answer to this I don't understand?

A group of students was asked about the number of flights they have taken. The data is shown in the line plot.

A line plot titled Flights Taken. The horizontal line begins at 7, with each unit marked up to 18. There is one dot above 10 and 11. There are two dots above 12, 13, and 14. There are four dots above 15.

Which of the following best describes the spread of the data? Explain its meaning in this situation.

The data has a range of 5, which is a wide spread. This means the greatest number of flights was 5.
The data has a range of 15, which is a narrow spread. This means that there is not a large difference in the number of flights taken by the students.
The data has a range of 5, which is a narrow spread. This means that most of the students have taken a similar number of flights.
The data has a range of 15, which is a wide spread. This means that there is a difference of 15 flights between each of the students.