A speed training service wants to explore the effectiveness of some of the classes offered to their clients. They randomly select 300 high school athletes and record their 50-meter dash time. The 300 high school athletes are then randomly assigned to three groups with 100 in each. One hundred athletes will take a circuit training class, 100 athletes will take an interval training class, and 100 athletes will take a plyometrics training class. At the end of 10 weeks of taking these classes, their 50-meter dash time will be recorded a second time. Their times will be analyzed to see which class showed the greatest overall improvement in times. Select all the sentences that correctly identify the components of the experiment.

The experimental units are subjects.

The subjects are the 50 athletes.

There is one treatment, the 50-meter dash.

There are three treatments.

One treatment is a circuit training class.

The factor is the type of class.

There are 10 levels of the factor.