Read the passage.

Many high school students enjoy working out. Some students enjoy sports, while others exercise independently. Running, swimming, and dancing provide great workouts. By the teen years, bodies are mature enough to add weight training. Lifting weights increases strength and improves coordination and balance. Weight-lifting routines must be planned carefully to avoid strain and injury.

Which detail explains the benefits of weight training?

Many high school students enjoy working out.
By the teen years, bodies are mature enough to add weight training.
Lifting weights increases strength and improves coordination and balance.
Weight-lifting routines must be planned carefully to avoid strain and injury.