Madden Motors is developing a new training program. The HR department wants to rigorously evaluate the effectiveness of their training program focused on safety knowledge. Which of the following represents the most rigorous training evaluation design?

Give all trainees a test to assess how much they learned in training.

Randomly assign two units at Madden Motors to a trained and untrained $($control$)$ condition. Give each unit a safety knowledge test before and after training.

Randomly assign two units at Madden Motors to a trained and untrained $($control$)$ condition. Give each unit a safety knowledge test after training.

Administer a safety knowledge test to all employees. Have all employees complete the safety knowledge training. After training, give all employees another safety knowledge test.