Final answer:
The cervical spine is the most mobile and delicate part of the spine, with seven vertebrae designed for a wide range of motion.The correct option is 1.
Step-by-step explanation:
The part of the spine that is the most mobile and delicate is the cervical spine. Consisting of seven cervical vertebrae (C1-7), these vertebrae have a small body, which reflects that they carry the least amount of body weight. They have several characteristic features, such as a bifid (Y-shaped) spinous process and transverse foramina in their transverse processes. Additionally, the superior and inferior articular processes of the cervical vertebrae are flattened and largely face upward or downward, allowing a greater range of motion, which is why the cervical spine possesses the greatest range for rotation.
Regarding the order of the vertebral regions from the closest to the head to the farthest, it would be: cervical, thoracic, lumbar, sacral, and coccygeal.