The box plot compares the number of events that Mrs. Cai's and Mr. Roland's classes won over the last 10 years on the school's field day. Based on the data in the box plots, what is the best evidence to show which class has had greater success on field day over the last 10 years? Mrs. Cai's class was more successful because her interquartile range was less spread out.

Mrs. Cai's class was more successful because she had the greater total spread.

Mr. Roland's class was more successful because his class always won at least one event.

Mr. Roland's class was more successful because his class's lower quartile was the same as Mrs. Cai's class's upper quartile.

Based on the information provided by the box plot, it can be seen that the smallest value of Mrs Cais class was 0 while that of My Roland's class was 1.

The lower quartile of Mrs Cais class was 2 while that of Mr Roland's class was 4.

The median of Mrs Cais class was 3 while that of Mr Roland's class was 5.

The upper quartile of Mrs Cais class was 4 while that of Mr Roland's class was 7.

Both of the classes has their highest value as 8.

From these information, it can be observed that Mr Roland's class was more successful because, as we can see, the upper quartile of Mrs Cais class was the lower quartile of Mr Roland's class.

The fourth option is the correct answer option.