A radiograph of an AP axial projection of the cervical spine…

A radiograph of an AP axial projection of the cervical spine reveals that the intervertebral joints are not open. The following analog factors were used for this projection: 5° cephalad angle, 40-inch (100-cm) SID, grid, slight extension of the skull, and the CR centered to the thyroid cartilage. Which of the following modifications should be made during the repeat exposure?