Which of the following is a cue to promote proper alignment during the exercises?

Engaging the core muscles is essential for promoting proper alignment during Pilates exercises. The core serves as a stabilizing force for the entire body, allowing for improved posture and alignment while performing movements. By focusing on core engagement, practitioners create a strong foundation that supports the spine and pelvis, helps maintain neutral alignment, and enables efficient movement patterns.

Additionally, core engagement encourages awareness of the body's position in space, leading to better control over movements and reducing the risk of injury. This focus on the core also enhances the effectiveness of the Pilates practice, as many exercises are designed to strengthen and stabilize this area.

In contrast, the other cues such as flexing the spine more, splaying the legs wider, or lifting the shoulders do not promote proper alignment. Instead, they may lead to misalignment or instability, which can be counterproductive to the goals of the practice. Proper alignment is foundational to executing exercises safely and effectively in Pilates, thereby emphasizing the importance of core engagement as the correct choice.