Hint: The spinal nerves from the cervical vertebrae in the cervical segment of the spinal cord are called the cervical nerves. The function of the cervical spine is to provide stability and mobility to the head. While also connecting it to the relatively immobile thoracic spine.
Complete answer: In humans, the vertebral column which is dorsally placed is formed by 26 serially arranged units called vertebrae.
A central hollow portion (neural canal) through which the spinal cord passes is present in each vertebra. The cervical nerves innervate the following muscles- sternohyoid, sternothyroid, and omohyoid muscles.
A loop of nerves which is part of the cervical plexus is called ansa cervicalis.
Ideally, there are as many pairs of a number of vertebrae as spinal nerves. In man, there are 31 pairs of spinal nerves present including 8 pairs of cervical nerves, 12 pairs of thoracic nerves, 5 pairs of lumbar nerves, 5 pairs of sacral 25. nerves and 1 pair of coccygeal nerves.
The vertebrae of the neck region are the cervical vertebrae. Their number is seven in all mammals whether the neck is short as in mouse or long as in a camel or giraffe, including man except some, e.g., sloths and the sea cows.
Hence, the correct answer is option A.
Note: The vertebral column starting from the skull is differentiated into cervical, thoracic, lumbar, sacral, and coccygeal regions. They are 7, 12,5, 1(fused), and 1(fused) in number. And hence, the number of vertebrae present is 7,12,5,1,1 on cervical, thoracic, lumbar, sacral, and coccyx regions respectively.