Match the following exercise to the muscle it primarily targets: Breast Stroke.

The Breast Stroke exercise primarily targets the Erector Spinae muscles. These muscles run along the spine and are crucial for maintaining an upright posture and supporting the back during extension movements. In the context of the Breast Stroke, as the arms reach forward and the chest lifts off the mat, the Erector Spinae are engaged to extend the spine and stabilize the torso against gravity.

This exercise not only strengthens these muscles but also encourages proper spinal alignment and enhances back flexibility. The movement is designed to provide a gentle yet effective workout that promotes the stability and strength needed for a healthy back, making the engagement of the Erector Spinae a focal point during the exercise.