Which of the following muscles helps in flexing the neck?

The levator scapulae primarily aids in flexing the neck, particularly when the neck is in a lateral flexion or when you are tilting your head down. This muscle is located at the back and side of the neck, originating from the cervical vertebrae and inserting into the scapula. It functions to elevate the scapula and assist in movements of the neck, including flexion along with lateral extension.

While the trapezius can assist in some aspects of neck movement, it is primarily known for its roles in shoulder movement and stabilizing the shoulder girdle. The latissimus dorsi mainly functions in movements of the shoulder and does not contribute to neck flexion. The rectus abdominis, while crucial in flexing the trunk, is not involved in the flexion of the neck. Hence, the levator scapulae is the muscle most directly responsible for flexing the neck.